Exhibit 99.1

STERIS CORPORATION

NEWS ANNOUNCEMENT

FOR IMMEDIATE RELEASE

STERIS CORPORATION ANNOUNCES FISCAL 2011 SECOND QUARTER RESULTS

• Operating margin expansion continues

• Full year outlook updated

Mentor, Ohio (November 3, 2010) - STERIS Corporation (NYSE: STE) today announced financial results for its fiscal 2011 second quarter ended September 30, 2010. Fiscal 2011 second quarter revenues were $312.4 million compared with $314.2 million in the second quarter of fiscal 2010, a decrease of 1%. Operating profit increased 10% to $54.9 million, or 17.6% of revenues, compared with $50.1 million, or 15.9% of revenues in the second quarter of fiscal 2010. Fiscal 2011 second quarter net income was $35.7 million, or $0.59 per diluted share, compared with net income of $32.1 million, or $0.54 per diluted share in the second quarter of fiscal 2010. Fiscal 2011 second quarter net income was impacted by the $110 million liability recorded in the first quarter for the SYSTEM 1 Rebate Program, which favorably impacted the Company’s tax rate, resulting in a benefit of $0.04 per diluted share during the quarter. Please see the attached schedules for more information, including comparisons excluding the impact of the SYSTEM 1 Rebate Program.

“During the second quarter, we continued to expand our operating margins, despite a slight decline in revenue,” said Walt Rosebrough, President and Chief Executive Officer of STERIS. “Given the strength in our surgical and Isomedix businesses and our expectations for the SYSTEM 1E transition, our revenue expectations are unchanged for the full year. In addition, we are raising the low end of our previous earnings per share guidance, resulting in a revised outlook of $2.15 to $2.30 per diluted share.”

Segment Results

Healthcare revenues in the quarter declined 1% to $220.1 million compared with $223.0 million in the second quarter of fiscal 2010. Service revenue declined 2% while consumable revenue declined 6% due to reductions in S20 volumes and lower H1N1 product sales as compared to the prior year. Capital equipment revenue grew 2%, reflecting growth in surgical products somewhat offset by a decline in our infection prevention products. Operating income increased 5% to $38.1 million compared with $36.4 million in last year’s second quarter driven by continued operating efficiencies.

STERIS Corporation

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Life Sciences second quarter revenues were $53.5 million compared with $54.4 million in the second quarter of fiscal 2010, a decrease of 2%. Modest growth in consumables was not enough to offset a decline in both capital equipment and service revenues. Life Sciences operating income was $9.4 million, an increase of 10% compared with the prior year second quarter.

Fiscal 2011 second quarter revenues for Isomedix Services were $38.0 million compared with $34.7 million in the same period last year, an increase of 9%. Revenue benefitted from increased volumes from core medical device Customers. Operating income was $10.0 million in the quarter compared with $7.4 million in the second quarter of last year.

First Half Results

Fiscal 2011 first half results are impacted by a $110 million liability recorded in the first quarter for the SYSTEM 1 Rebate Program. Of the $110 million pre-tax amount recorded, $102 million is attributable to the Customer Rebate portion of the Program and was recorded as a reduction of revenues, and $8 million is attributable to the disposal of the SYSTEM 1 units to be returned and was recorded as an increase in cost of revenues. As a result, first half revenues were $501.4 million compared with $597.8 million in the first half of fiscal 2010. In addition, the company reported a net loss of $9.5 million, or ($0.16) per diluted share, compared with net income of $57.6 million, or $0.97 per diluted share, in the same period last year. Please refer to the attached schedules for additional information, including the Company’s financial results excluding the impact of the SYSTEM 1 Rebate Program.

Cash Flow

Net cash provided by operations for the first half of fiscal 2011 was $56.3 million, compared with $92.4 million in the same period last year. Free cash flow (see note 1) for the first half of fiscal 2011 was $29.3 million, compared with $74.4 million in the prior year period. The decline in free cash flow was driven by increased working capital requirements, primarily associated with increased inventory for SYSTEM 1E, and higher capital spending levels.

During the quarter, the Company repurchased 534,000 shares of its common stock at an average price of $30.32 per common share for a total amount of $16.2 million. Approximately $188 million remains under the current share repurchase authorization.

STERIS Corporation

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Dividend Announcement

The Company also announced today that STERIS’s Board of Directors has authorized a quarterly dividend of $0.15 per common share. The dividend is payable December 22, 2010 to shareholders of record at the close of business on November 24, 2010.

Outlook

Based upon current trends, the Company’s expectations for fiscal 2011 revenue growth of approximately 5% are unchanged. Earnings per diluted share are now anticipated to be in the range of $2.15 to $2.30, compared with prior expectations of $2.00 to $2.30 for the full fiscal year. This outlook reflects certain key assumptions, some of which are listed below:

• Healthcare revenue growth is expected to be in the mid-single digits.

• Life Sciences revenue is expected to decline in the low-single digits.

• Isomedix revenue growth is expected to be in the mid-to-high single digits.

• Excludes the reduction of revenue, operating income and tax rate related to the previously announced SYSTEM 1 Rebate Program.

• The Company has assumed the average forward exchange rates for the U.S. dollar and key international currencies as of September 30, 2010.

• The Company has assumed raw material costs will be approximately flat year over year.

• Excludes restructuring expenses from the Company’s ongoing efficiency efforts.

• EBIT as a percent of revenue is anticipated to be approximately 16.5%.

• The anticipated effective tax rate is approximately 36%.

For the full fiscal year 2011, free cash flow (see note 1) is currently anticipated to be in the range of $125 to $135 million and capital expenditures are currently anticipated to be in the range of $70 to $80 million.

Conference Call

In conjunction with this release, STERIS Corporation management will host a conference call today at 10:00 a.m. Eastern time. The conference call can be heard live over the Internet at www.steris-

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ir.com or via phone by dialing 1-800-369-8428 in the United States and Canada, and 1-773-799-3378 internationally, then referencing the password “STERIS”.

For those unable to listen to the conference call live, a replay will be available from 12:00 p.m. Eastern time on November 3, 2010, until 5:00 p.m. Eastern time on November 17, 2010, either over the Internet at www.steris-ir.com or via phone by calling 1-800-879-6722 in the United States and Canada, and 1-402-220-4751 internationally.

About STERIS

The mission of STERIS Corporation is to provide a healthier today and safer tomorrow through knowledgeable people and innovative infection prevention, decontamination and health science technologies, products and services. The Company has approximately 5,000 dedicated employees around the world working together to supply a broad array of solutions by offering a combination of equipment, consumables and services to healthcare, pharmaceutical, industrial and government Customers. The Company is listed on the New York Stock Exchange under the symbol STE. For more information, visit www.steris.com.

Contact: Julie Winter, Director, Investor Relations at 440-392-7245.

(1) Free cash flow is a non-GAAP number used by the Company as a measure to gauge its ability to fund future growth opportunities, repurchase common shares, and pay cash dividends. Free cash flow is defined as cash flows from operating activities less purchases of property, plant, equipment and intangibles, net, plus proceeds from the sale of property, plant, equipment and intangibles. STERIS’s calculation of free cash flow may vary from other companies.

# # #

This news release and the referenced conference call may contain statements concerning certain trends, expectations, forecasts, estimates, or other forward-looking information affecting or relating to the Company or its industry or products that are intended to qualify for the protections afforded “forward-looking statements” under the Private Securities Litigation Reform Act of 1995 and other laws and regulations. Forward-looking statements speak only as to the date of this report, and may be identified by the use of forward-looking terms such as “may,” “will,” “expects,” “believes,” “anticipates,” “plans,” “estimates,” “projects,” “targets,” “forecasts,” “outlook,” “potential,” “confidence,” “improve,” “optimistic,” “comfortable,” “trend”, and “seeks,” or the negative of such terms or other variations on such terms or comparable terminology. Many important factors could cause actual results to differ materially from those in the forward-looking statements including, without limitation, disruption of production or supplies, changes in market conditions, political events, pending or future claims or litigation, competitive factors, technology advances, actions of regulatory agencies, and changes in laws, government regulations, labeling or product approvals, or the application or interpretation thereof. Other risk factors are described in the Company’s Form 10-K and other securities filings. Many of these important factors are outside STERIS’s

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control. No assurances can be provided as to any outcome from litigation, regulatory action, administrative proceedings, government investigations, warning letters, consent decree, rebate program, transition, cost reductions, business strategies, earnings and revenue trends, expense reduction or other future financial results. Reference to the consent decree, transition, rebate program, or products are summaries only and do not alter or modify the specific terms of the decree, program or product clearance or literature. Unless legally required, the Company does not undertake to update or revise any forward-looking statements even if events make clear that any projected results, express or implied, will not be realized. Other potential risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements include, without limitation, (a) the potential for increased pressure on pricing that leads to erosion of profit margins, (b) the possibility that market demand will not develop for new technologies, products or applications, or the Company’s rebate program, transition plan, or other business initiatives will take longer, cost more or produce lower benefits than anticipated, (c) the possibility that application of or compliance with laws, court rulings, certifications, regulations, regulatory actions, including without limitation those relating to the previously disclosed FDA warning letters, government investigations, the December 3, 2009 or February 22, 2010 FDA notices, the April 20, 2010 consent decree and related transition plan and rebate program, the SYSTEM 1E device, the Reliance EPS System, or other requirements or standards, may delay, limit or prevent new product introductions or the production and marketing of existing products, or otherwise affect Company performance, results, or value, (d) the potential of international unrest or effects of fluctuations in currencies, tax assessments or rates, raw material costs, benefit or retirement plan costs, or other regulatory compliance costs, (e) the possibility of reduced demand, or reductions in the rate of growth in demand, for the Company’s products and services, (f) the possibility that anticipated growth, cost savings, rebate assumptions, new product acceptance or approvals, including without limitation, SYSTEM 1E and accessories thereto, or other results may not be achieved, or that transition, labor, competition, timing, execution, regulatory, governmental, or other issues or risks associated with the matters described in this release or the operation of the Company’s business, may adversely impact Company performance, results, or value, (g) the effect of the contraction in credit availability, as well as the ability of our customers and suppliers to adequately access the credit markets when needed, and (h) those risks described in our Annual Report on Form 10-K for the year ended March 31, 2010 and the form 10-Q for the quarter ended June 30, 2010.

STERIS Corporation

Consolidated Condensed Statements of Operations

(In thousands, except per share data)

	Three Months Ended September 30,					Six Months Ended September 30,
	2010		2009			2010			2009
	(Unaudited)		(Unaudited)			(Unaudited)			(Unaudited)
Revenues	$	312,425	$	314,229		$	603,718		$	597,772
SYSTEM 1 Rebate Program		—		—			(102,313	)		—
Revenues, net		312,425		314,229			501,405			597,772
Cost of revenues		177,370		181,574			340,593			340,281
Cost of revenues - SYSTEM 1 Rebate Program		—		—			7,691			—
Gross profit		135,055		132,655			153,121			257,491
Operating expenses:
Selling, general, and administrative		71,999		74,516			144,116			149,121
Research and development		8,043		8,189			16,652			15,769
Restructuring expense		105		(115	)		446			(327	)
Total operating expenses		80,147		82,590			161,214			164,563
Income (Loss) income from operations		54,908		50,065			(8,093	)		92,928
Non-operating expense, net		2,808		2,852			5,653			5,718
Income tax expense		16,389		15,129			(4,247	)		29,584
Net (loss) income	$	35,711	$	32,084		$	(9,499	)	$	57,626
Earnings per common share (EPS) data:
Basic	$	0.60	$	0.55		$	(0.16	)	$	0.98
Diluted	$	0.59	$	0.54		$	(0.16	)	$	0.97
Cash dividends declared per common share outstanding	$	0.15	$	0.11		$	0.26		$	0.22
Weighted average number of common shares outstanding used in EPS computation:
Basic number of common shares outstanding		59,356		58,654			59,377			58,585
Diluted number of common shares outstanding		60,049		59,242			59,377			59,042

STERIS Corporation

Consolidated Condensed Balance Sheets

(In thousands)

	September 30, 2010		March 31, 2010
	(Unaudited)
Assets
Current assets:
Cash and cash equivalents	$	217,403	$	214,971
Accounts receivable, net		201,758		214,940
Inventories, net		144,933		121,135
Other current assets		63,515		25,411
Total Current Assets		627,609		576,457
Property, plant, and equipment, net		348,137		346,858
Goodwill and intangible assets, net		308,749		305,311
Other assets		9,911		9,776
Total Assets	$	1,294,406	$	1,238,402
Liabilities and Equity
Current liabilities:
Accounts payable	$	65,492	$	66,035
Accrued SYSTEM 1 Rebate Program		109,956		—
Other current liabilities		106,724		131,094
Total Current Liabilities		282,172		197,129
Long-term debt		210,000		210,000
Other liabilities		71,782		76,779
Equity		730,452		754,494
Total Liabilities and Equity	$	1,294,406	$	1,238,402

STERIS Corporation

Income Reconciliation

(In thousands, except per share data)

The following table presents financial measures which are considered to be “non-GAAP financial measures” under Securities Exchange Commission rules. The Company has referred to results of operations excluding the SYSTEM 1 Rebate Program and related disposal costs to provide meaningful comparative analysis between the periods.

	Three months ended September 30, 2010									Six months ended September 30, 2010
	Results of Operations, excluding Rebate Program			Impact of SYSTEM 1 Rebate Program			As reported			Results of Operations, excluding Rebate Program			Impact of SYSTEM 1 Rebate Program			As reported
	(Unaudited)									(Unaudited)
Revenues	$	312,425		$	—		$	312,425		$	603,718		$	(102,313	)	$	501,405
Cost of revenues		177,370			—			177,370			340,593			7,691			348,284
Gross profit		135,055			—			135,055			263,125			(110,004	)		153,121
Operating expenses		80,147			—			80,147			161,214			—			161,214
Income (loss) from operations		54,908			—			54,908			101,911			(110,004	)		(8,093	)
Non-operating expenses, net		2,808			—			2,808			5,653			—			5,653
Income (loss) before income taxes		52,100			—			52,100			96,258			(110,004	)		(13,746	)
Income tax (benefit) expense		19,093			(2,704	)		16,389			35,413			(39,660	)		(4,247	)
Net income (loss)	$	33,007		$	2,704		$	35,711		$	60,845		$	(70,344	)	$	(9,499	)
Net income (loss) per common share:
Basic	$	0.56		$	0.04		$	0.60		$	1.02		$	(1.18	)	$	(0.16	)
Diluted	$	0.55		$	0.04		$	0.59		$	1.01		$	(1.17	)	$	(0.16	)
Weighted average number of common shares outstanding used in EPS computation:
Basic		59,356						59,356			59,377						59,377
Diluted		60,049						60,049			60,153						59,377
Effective income tax rate		36.6	%					31.5	%		36.8	%					30.9	%

STERIS Corporation

Segment Data & Income Analysis

(In thousands)

	Three Months Ended September 30,				Six Months Ended September 30,
	2010		2009		2010			2009
	(Unaudited)		(Unaudited)		(Unaudited)			(Unaudited)
Segment Revenues:
Healthcare	$	220,114	$	223,006	$	426,193		$	423,610
SYSTEM 1 Rebate Program		—		—		(102,313	)		—
Healthcare, net		220,114		223,006		323,880			423,610
Life Sciences		53,513		54,401		100,127			100,517
STERIS Isomedix Services		37,964		34,735		75,640			70,142
Total Reportable Segments		311,591		312,142		499,647			594,269
Corporate and Other		834		2,087		1,758			3,503
Total Segment Revenues	$	312,425	$	314,229	$	501,405		$	597,772

The following table presents financial measures which are considered to be “non-GAAP financial measures” under Securities Exchange Commission rules. The Company has referred to results of operations excluding the SYSTEM 1 Rebate Program and related disposal costs to provide meaningful comparative analysis between the periods.

	Three Months Ended September 30,
	2010							2009
	(Unaudited)							(Unaudited)
	As Reported			SYSTEM 1 Rebate Program		Total		Total As Reported
Segment Operating (Loss) Income Excluding SYSTEM 1 Rebate program:
Healthcare	$	38,063		$	—	$	38,063	$	36,366
Life Sciences		9,435			—		9435		8,540
STERIS Isomedix Services		10,024			—		10024		7,401
Total Reportable Segments		57,522			—		57522		52,307
Corporate and Other		(2,614	)		—		-2614		(2,242	)
Total Operating (Loss) Income	$	54,908		$	—	$	54,908	$	50,065

	Six Months Ended September 30,
	2010								2009
	(Unaudited)								(Unaudited)
	As Reported			SYSTEM 1 Rebate Program			Total		Total As Reported
Segment Operating (Loss) Income Excluding SYSTEM 1 Rebate program:
Healthcare	$	(39,849	)	$	(110,004	)	$	70,155	$	68,469
Life Sciences		15,730			—			15730		13,319
STERIS Isomedix Services		20,608			—			20608		15,740
Total Reportable Segments		(3,511	)		(110,004	)		106493		97,528
Corporate and Other		(4,582	)		—			-4582		(4,600	)
Total Operating (Loss) Income	$	(8,093	)	$	(110,004	)	$	101,911	$	92,928

STERIS Corporation

Consolidated Condensed Statements of Cash Flows

(In thousands)

	Six Months Ended
	September 30,
	2010			2009
	(Unaudited)			(Unaudited)
Operating Activities:
Net (loss) income	$	(9,499	)	$	57,626
Non-cash items		(7,629	)		32,945
Change in Accrued SYSTEM 1 Rebate Program		109,956			—
Changes in operating assets and liabilities		(36,471	)		1,837
Net cash provided by operating activities		56,357			92,408
Investing Activities:
Purchases of property, plant, equipment, and intangibles, net		(27,242	)		(18,543	)
Proceeds from sale of property, plant, equipment and intangibles		192			509
Net cash used in investing activities		(27,050	)		(18,034	)
Financing Activities:
Repurchases of common shares		(16,627	)		(289	)
Cash dividends paid to common shareholders		(15,459	)		(12,894	)
Stock option and other equity transactions, net		3,290			2,102
Tax benefit from stock options exercised		786			463
Net cash used in financing activities		(28,010	)		(10,618	)
Effect of exchange rate changes on cash and cash equivalents		1,135			5,822
Increase in cash and cash equivalents		2,432			69,578
Cash and cash equivalents at beginning of period		214,971			154,180
Cash and cash equivalents at end of period	$	217,403		$	223,758

The following table presents a financial measure which is considered to be “non-GAAP financial measures” under Securities Exchange Commission rules. Free cash flow is defined by the Company as cash flows from operating activities less purchases of property, plant, equipment and intangibles, net (capital expenditures) plus proceeds from the sale of property, plant, equipment and intangibles. The Company uses free cash flow as a measure to gauge its ability to fund future growth opportunities, repurchase common shares, and pay cash dividends. STERIS’s calculation of free cash flow may vary from other companies.

	Six Months Ended September 30,
	2010			2009
	(Unaudited)			(Unaudited)
Calculation of Free Cash Flow:
Cash flows from operating activities	$	56,357		$	92,408
Purchases of property, plant, equipment, and intangibles, net		(27,242	)		(18,543	)
Proceeds from the sale of property, plant, equipment, and intangibles		192			509
Free Cash Flow	$	29,307		$	74,374

STERIS Corporation

Unaudited Supplemental Financial Data - Excluding SYSTEM 1 Rebate Program

Second Quarter Fiscal 2011

As of September 30, 2010

	FY 2011			FY 2011			FY 2010			FY 2010
	Q2			YTD			Q2			YTD
Total Company Revenues
Capital	$	120,308		$	223,560		$	119,146		$	211,849
Consumables		76,784			153,117			79,989			160,786
Service		115,333			227,041			115,094			225,137
Total Recurring		192,117			380,158			195,083			385,923
Total Revenues	$	312,425			603,718		$	314,229		$	597,772
United States Revenues	$	237,953			464,041		$	238,292		$	462,098
United States Revenues as a % of Total		76	%		77	%		76	%		77	%
International Revenues	$	74,472		$	139,677		$	75,937		$	135,674
International Revenues as % of Total		24	%		23	%		24	%		23	%
	Q2			YTD			Q2			YTD
Segment Data
Healthcare
Revenues
Capital	$	101,580		$	190,918		$	99,737		$	176,574
Consumables		60,443			120,925			64,038			130,769
Service		58,091			114,350			59,231			116,267
Total Recurring		118,534			235,275			123,269			247,036
Total Healthcare Revenues	$	220,114		$	426,193		$	223,006		$	423,610
Operating Income (Loss)		38,063			70,155			36,366			68,469
Life Sciences
Revenues
Capital	$	18,728		$	32,642		$	19,374		$	35,240
Consumables		16,341			32,192			15,951			30,017
Service		18,444			35,293			19,076			35,260
Total Recurring		34,785			67,485			35,027			65,277
Total Life Sciences Revenues	$	53,513		$	100,127		$	54,401		$	100,517
Operating Income (Loss)		9,435			15,730			8,540			13,319
Isomedix Services
Revenues	$	37,964		$	75,640		$	34,735		$	70,142
Operating Income (Loss)		10,024			20,608			7,401			15,740
Corporate and Other
Revenues	$	834		$	1,758		$	2,087		$	3,503
Operating Income (Loss)		(2,614	)		(4,582	)		(2,242	)		(4,600	)
	Q2			YTD			Q2			YTD
Other Data
Healthcare Backlog	$	154,273			n/a		$	129,937			n/a
Life Sciences Backlog		37,952			n/a			46,492			n/a
Total Backlog	$	192,225			n/a		$	176,429			n/a
Free Cash Flow	$	12,021		$	29,307		$	49,934		$	74,374
Net Debt	$	(7,403	)	$	(7,403	)	$	(13,758	)	$	(13,758	)

This supplemental data is consistent with publicly disclosed information provided in quarterly conference calls, earnings releases and SEC filings, and is subject to all definitions, precautions and limitations contained in those disclosures. Please see the Company’s most recent 10-K for definitions (and reconciliation where appropriate) of backlog, free cash flow and net debt.