Exhibit 99.1

INVESTOR CONTACT	MEDIA CONTACT
Scott Wylie — Vice President	Mark Plungy — Senior Manager
Investor Relations	Public Relations
(408) 544-6996	(408) 544-6397
swylie@altera.com	newsroom@altera.com

ALTERA ANNOUNCES RECORD SECOND QUARTER RESULTS
INCREASES QUARTERLY DIVIDEND

San Jose, Calif., July 20, 2010—Altera Corporation (NASDAQ: ALTR) today announced second quarter sales of $469.3 million, up 17 percent from the first quarter of 2010 and up 68 percent from the second quarter of 2009. New product sales increased 36 percent sequentially. Second quarter net income was $180.6 million, $0.58 per diluted share, compared with net income of $153.2 million, $0.50 per diluted share, in the first quarter of 2010 and $47.4 million, $0.16 per diluted share, in the second quarter of 2009.

Year-to-date cash flow from operating activities was $378.6 million. Altera ended the quarter with $2.1 billion in cash and short-term investments.

Altera’s board of directors has increased the company’s quarterly cash dividend to $0.06 per share, up from the previous dividend of $0.05 per share. The board of directors has declared that the next quarterly dividend will be paid on September 1, 2010 to stockholders of record on August 10, 2010.

“In the second quarter, our 65-nm FPGA revenue was once again up sharply. Our newer 40-nm products grew even faster as they transition into the production-demand phase of their life,” said John Daane, president, chief executive officer, and chairman of the board. “Development work on our next-generation 28-nm FPGAs is reaching its final stages. The unique innovations in these FPGAs, including 28-Gbps transceivers, will extend the technology leadership that has benefited us so strongly at the 40-nm node.”

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Several recent accomplishments mark the company’s continuing progress:

• Altera’s Quartus^® II v10.0 software, used in support of Altera’s 28-nm Stratix^® V family, is now available. Altera is the only FPGA supplier with publicly available software for its 28-nm FPGAs. This version incorporates support for Stratix V GX and Stratix V GS FPGAs and offers several new productivity and performance features with high-density compile times two to three times faster than the nearest competitor.

• With the arrival of production shipments of the Stratix IV E EP4SE820 device, the highest density member of the Stratix IV FPGA family, Altera’s entire Stratix IV FPGA family is shipping in production-qualified volume. Stratix IV FPGAs are the industry’s highest density, highest performance and lowest power FPGAs currently shipping in their class. This device family features proven transceiver and memory-interface technology, providing an ideal solution for customers in a variety of end markets. Altera’s high-end FPGAs feature three variants, a non-transceiver enhanced (E) version and two transceiver (GX and GT) versions. The Stratix IV E FPGAs are high in density and rich with embedded memory and DSP resources. Stratix IV GX and Stratix IV GT variants feature integrated transceivers that operate up to 8.5 Gbps and 11.3 Gbps, respectively, providing an unprecedented level of system bandwidth with superior signal integrity.

• Altera has received the “Best 3G Communication FPGA Supplier Award” from China Electronic News (CEN). CEN’s award is in recognition of Altera’s contribution to China’s telecommunication industry, especially China’s successful 3G deployment in the past few years. Each year, CEN selects companies that lead the industry in innovation or have outstanding market performance in various segments of the China telecommunication market. The awards are determined by a committee comprised of industry and university technology experts and members of CEN’s senior editorial team. Members of the selection committee voted based on three criteria: technology innovation, market influence and product service. CEN, with a circulation of 200,000 in China, is the most authoritative publication covering China’s electronics information industry.

• Altera has been presented with the TechAmerica Foundation’s American Technology Award. Winning in the electronics components category, the award recognizes the Stratix IV GT FPGA for enabling next-generation communications infrastructure to support growing bandwidth requirements. Altera’s Stratix IV GT FPGAs are optimized specifically for the latest generation of 40G and 100G applications used in communications systems, high-end test equipment and military communications systems. The FPGAs feature high-speed 11.3-Gbps transceivers to support high-throughput system requirements, as well as core performance and logic density to handle the complex processing needed in these systems.

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Business Outlook for the Third Quarter 2010

Sequential Sales Growth	Up 4% to 8%
Gross Margin	70% to 71%
Research and Development	$	69 to 70 million
SG&A	$	64 to 65 million
Tax Rate	12% to 14%

Conference Call and Quarterly Update:

A conference call will be held today at 1:45 p.m. Pacific Time to discuss the quarter’s results and management’s current business outlook. The webcast and subsequent replay will be available in the Investor Relations section of the company’s website at www.altera.com. A telephonic replay of the call may be accessed later in the day by calling (719) 457-0820 and referencing confirmation code 258712. The telephonic replay will be available for two weeks following the live call.

Altera’s third quarter business update will be issued in a press release available after the market close on September 7, 2010.

Forward-Looking Statements

Statements in this press release that are not historical are “forward-looking statements” as the term is defined in the Private Securities Litigation Reform Act of 1995. Forward-looking statements are generally written in the future tense and/or preceded by words such as “will,” “expects,” “anticipates,” or other words that imply or predict a future state. Forward-looking statements include any projection of revenue, gross margin, expense or other financial items discussed in the Business Outlook section of this press release, and the potential for continued technology leadership at 28 nm. Investors are cautioned that all forward-looking statements in this release involve risks and uncertainty that can cause actual results to differ from those currently anticipated, due to a number of factors, including without limitation, current global economic conditions, customer business environment, vertical market mix, market acceptance of the company’s products, product introduction schedules, the rate of growth of the company’s new products including Arria^® II, Cyclone^® III, Stratix^® III, Stratix IV, and Stratix V FPGAs, MAX^® II CPLDs and HardCopy^® device families, changes in the mix of our business between prototyping and production-based demand, as well as changes in economic conditions and other risk factors discussed in documents filed by the company with the Securities and Exchange

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Commission (SEC) from time to time. Copies of Altera’s SEC filings are posted on the company’s website and are available from the company without charge. Forward-looking statements are made as of the date of this release, and, except as required by law, the company does not undertake an obligation to update its forward-looking statements to reflect future events or circumstances.

About Altera

Altera programmable solutions enable system and semiconductor companies to rapidly and cost-effectively innovate, differentiate and win in their markets. Find out more about Altera’s FPGA, CPLD and ASIC devices at www.altera.com. Follow Altera via Facebook, RSS and Twitter.

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Altera, The Programmable Solutions Company, the stylized Altera logo, specific device designations and all other words that are identified as trademarks and/or service marks are, unless noted otherwise, the trademarks and service marks of Altera Corporation in the U.S. and other countries. All other product or service names are the property of their respective holder.

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ALTERA CORPORATION
CONSOLIDATED STATEMENTS OF INCOME
(In thousands, except per share data)
(Unaudited)

	THREE MONTHS ENDED									SIX MONTHS ENDED
	July 2,			April 2,			June 26,			July 2,			June 26,
	2010			2010			2009			2010			2009
Net sales	$	469,300		$	402,295		$	279,201		$	871,595		$	543,803
Cost of sales		132,811			114,936			93,588			247,747			187,617
Gross margin		336,489			287,359			185,613			623,848			356,186
Operating expenses
Research and development		65,625			64,340			64,981			129,965			123,171
Selling, general, and administrative		64,767			62,181			53,679			126,948			114,338
Total operating expenses		130,392			126,521			118,660			256,913			237,509
Operating margin(1)		206,097			160,838			66,953			366,935			118,677
Compensation (benefit)/expense — deferred compensation plan		(3,642	)		2,228			3,586			(1,414	)		3,609
Loss/(gain) on deferred compensation plan securities		3,642			(2,228	)		(3,586	)		1,414			(3,609	)
Interest income and other		(710	)		(592	)		(1,717	)		(1,302	)		(5,095	)
Interest expense		1,103			1,291			1,321			2,394			2,659
Income before income taxes		205,704			160,139			67,349			365,843			121,113
Income tax expense		25,097			6,966			19,926			32,063			29,729
Net income	$	180,607		$	153,173		$	47,423		$	333,780		$	91,384
Net income per share:
Basic	$	0.59		$	0.51		$	0.16		$	1.11		$	0.31
Diluted	$	0.58		$	0.50		$	0.16		$	1.09		$	0.31
Shares used in computing per share amounts:
Basic		304,531			298,566			293,895			301,532			293,511
Diluted		310,757			304,327			295,503			307,526			295,157
Cash dividends per common share	$	0.05		$	0.05		$	0.05		$	0.10		$	0.10
Tax rate		12.2	%		4.3	%		29.6	%		8.8	%		24.5	%
% of Net sales:
Gross margin		71.7	%		71.4	%		66.5	%		71.6	%		65.5	%
Research and development		14.0	%		16.0	%		23.3	%		14.9	%		22.6	%
Selling, general, and administrative		13.8	%		15.5	%		19.2	%		14.6	%		21.0	%
Operating margin(1)		43.9	%		40.0	%		24.0	%		42.1	%		21.8	%
Net income		38.5	%		38.1	%		17.0	%		38.3	%		16.8	%

Notes:

(1) We define operating margin as gross margin less research and development and selling, general and administrative expenses, as presented above. This presentation differs from income from operations as defined by U.S. Generally Accepted Accounting Principles (“US GAAP”), as it excludes the effect of compensation associated with the deferred compensation plan obligations. Since the effect of compensation associated with our deferred compensation plan obligations is offset by losses (gains) from related securities, we believe this presentation provides a more meaningful representation of our ongoing operating performance. A reconciliation of operating margin to income from operations follows:

	THREE MONTHS ENDED							SIX MONTHS ENDED
	July 2,			April 2,		June 26,		July 2,			June 26,
	2010			2010		2009		2010			2009
Operating margin (non-GAAP)	$	206,097		$	160,838	$	66,953	$	366,935		$	118,677
Compensation (benefit)/expense — deferred compensation plan		(3,642	)		2,228		3,586		(1,414	)		3,609
Income from operations (GAAP)	$	209,739		$	158,610	$	63,367	$	368,349		$	115,068

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ALTERA CORPORATION
CONSOLIDATED BALANCE SHEETS
(In thousands, except par value amounts)
(Unaudited)

	July 2,			December 31,
	2010			2009
Assets
Current assets:
Cash and cash equivalents	$	2,067,215		$	1,546,672
Accounts receivable, net		358,006			218,144
Inventories		99,955			69,705
Deferred income taxes — current		88,438			79,164
Deferred compensation plan — marketable securities		47,050			50,905
Deferred compensation plan — restricted cash equivalents		18,053			18,986
Other current assets		72,656			58,194
Total current assets		2,751,373			2,041,770
Property and equipment, net		165,432			174,516
Deferred income taxes — non-current		47,384			59,249
Other assets, net		18,801			17,696
Total assets	$	2,982,990		$	2,293,231
Liabilities and stockholders’ equity
Current liabilities:
Accounts payable	$	110,088		$	50,520
Accrued liabilities		19,857			32,256
Accrued compensation and related liabilities		63,656			49,862
Deferred compensation plan obligations		65,103			69,891
Deferred income and allowances on sales to distributors		395,429			281,885
Income taxes payable		6,569			5,547
Total current liabilities		660,702			489,961
Income taxes payable — non-current		220,204			210,967
Long-term credit facility		500,000			500,000
Other non-current liabilities		7,133			6,967
Total liabilities		1,388,039			1,207,895
Stockholders’ equity:
Common stock: $.001 par value; 1,000,000 shares authorized; outstanding— 305,857 at July 2, 2010 and 296,817 at December 31, 2009		306			297
Capital in excess of par value		582,348			372,098
Retained earnings		1,012,297			712,941
Total stockholders’ equity		1,594,951			1,085,336
Total liabilities and stockholders’ equity	$	2,982,990		$	2,293,231
Key Ratios & Information
Current Ratio		4:1			4:1
Liabilities/Equity		1:1			1:1
Quarterly Operating Cash Flows	$	245,921		$	176,352
TTM Return on Equity		42	%		27	%
Quarterly Depreciation Expense	$	6,403		$	6,839
Quarterly Capital Expenditures	$	2,812		$	1,824
Annualized Net Sales per Employee	$	680		$	450
Number of Employees		2,579			2,551
Inventory MSOH (1): Altera		2.3			1.8
Inventory MSOH (1): Distribution		0.9			0.7
Cash Conversion Cycle		80			77

(1) MSOH: Months Supply On Hand

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ALTERA CORPORATION
CONSOLIDATED STATEMENTS OF CASH FLOWS
(In thousands)
(Unaudited)

	Six Months Ended
	July 2,			June 26,
	2010			2009
Cash Flows from Operating Activities:
Net income	$	333,780		$	91,384
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		13,504			14,714
Stock-based compensation		29,749			30,435
Deferred income tax benefit		(11,296	)		(6,286	)
Tax effect of employee stock plans		6,996			(1,897	)
Excess tax benefit from employee stock plans		(6,465	)		(231	)
Gain on substantive termination of retiree medical plan		—			(6,488	)
Changes in assets and liabilities:
Accounts receivable, net		(139,862	)		(112,640	)
Inventories		(30,250	)		18,418
Other assets		(15,637	)		30,018
Accounts payable and other liabilities		63,756			(21,019	)
Deferred income and allowances on sales to distributors		113,544			27,160
Income taxes payable		24,146			26,037
Deferred compensation plan obligations		(3,374	)		1,266
Net cash provided by operating activities		378,591			90,871
Cash Flows from Investing Activities:
Purchases of property and equipment		(4,350	)		(6,852	)
Sales (purchases) of deferred compensation plan securities, net		3,374			(1,266	)
Purchases of intangible assets		—			(510	)
Net cash used in investing activities		(976	)		(8,628	)
Cash Flows from Financing Activities:
Proceeds from issuance of common stock through various stock plans		175,386			11,933
Shares withheld for employee taxes		(6,159	)		(4,655	)
Payment of dividends to stockholders		(30,137	)		(29,370	)
Excess tax benefit from stock-based compensation		6,465			231
Principal payments on capital lease obligations		(2,627	)		(2,150	)
Net cash provided by (used in) financing activities		142,928			(24,011	)
Net increase in cash and cash equivalents		520,543			58,232
Cash and cash equivalents at beginning of period		1,546,672			1,216,743
Cash and cash equivalents at end of period	$	2,067,215		$	1,274,975

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ALTERA CORPORATION
NET SALES SUMMARY
(Unaudited)

										Quarterly Growth Rate
	THREE MONTHS ENDED												Year-
	July 2,			April 2,			June 26,			Sequential			Over-Year
	2010			2010			2009			Change			Change
Geography
Americas		20	%		19	%		20	%		18	%		66	%
Asia Pacific		41	%		40	%		43	%		22	%		61	%
EMEA		24	%		24	%		21	%		14	%		86	%
Japan		15	%		17	%		16	%		6	%		65	%
Total		100	%		100	%		100	%		17	%		68	%
Product Category
New		40	%		34	%		22	%		36	%		199	%
Mainstream		29	%		30	%		34	%		13	%		46	%
Mature & Other		31	%		36	%		44	%		1	%		18	%
Total		100	%		100	%		100	%		17	%		68	%
Vertical Market
Telecom & Wireless		42	%		40	%		48	%		21	%		45	%
Industrial Automation, Military & Auto		23	%		24	%		21	%		14	%		87	%
Networking, Computer & Storage		13	%		13	%		13	%		21	%		74	%
Other		22	%		23	%		18	%		11	%		103	%
Total		100	%		100	%		100	%		17	%		68	%
FPGAs and CPLDs
FPGA		82	%		79	%		76	%		20	%		81	%
CPLD		12	%		14	%		16	%		-1	%		28	%
Other		6	%		7	%		8	%		11	%		30	%
Total		100	%		100	%		100	%		17	%		68	%

Product Category Description

Category	Products
New	Stratix III, Stratix IV (including E, GX and GT), Arria II GX, Cyclone III, Cyclone IV GX, MAX II, and HardCopy III devices
Mainstream	Stratix II (and GX), Arria GX, Cyclone II, and HardCopy II devices
Mature & Other	Stratix (and GX), Cyclone, Classic™, MAX 3000A, MAX 7000, MAX 7000A, MAX 7000B, MAX 7000S, MAX 9000, HardCopy, FLEX® series, APEX™ series, Mercury™, Excalibur™, configuration and other devices, intellectual property cores, and software and other tools

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