Exhibit 5.1

233 S. Wacker Drive, Suite 5800
Chicago, Illinois 60606
Tel: +1.312.876.7700 Fax: +1.312.993.9767
www.lw.com

	FIRM / AFFILIATE OFFICES
	Abu Dhabi	Moscow
	Barcelona	Munich
	Beijing	New Jersey
	Brussels	New York
	Chicago	Orange County
	Doha	Paris
	Dubai	Riyadh
	Frankfurt	Rome
	Hamburg	San Diego
	Hong Kong	San Francisco
	Houston	Shanghai
	London	Silicon Valley
	Los Angeles	Singapore
	Madrid	Tokyo
	Milan	Washington, D.C.

May 20, 2010

IDEX Corporation
630 Dundee Road
Northbrook, Illinois

          Re: Registration Statement on Form S-8 with respect to 3,500,000 shares of Common Stock, par value $0.01 per share

Ladies and Gentlemen:

     We have acted as counsel to IDEX Corporation, a Delaware corporation (the “Company”), in connection with the proposed issuance of up to 3,500,000 shares of common stock, par value $0.01 per share (the “Shares”), issuable pursuant to the IDEX Corporation Incentive Award Plan (As Amended and Restated) (the “Plan”). The Shares are included in a registration statement on Form S-8 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on May 20, 2010 (the “Registration Statement”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or related Prospectus, other than as expressly stated herein with respect to the issuance of the Shares.

     As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the General Corporation Law of the State of Delaware, and we express no opinion with respect to any other laws.

     Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when the Shares have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the recipient, and have been issued by the Company in the manner contemplated by the Plan, including the receipt of payment for such Shares in an amount in cash or other legal consideration of not less than the aggregate par value for such Shares, the issuance and sale of the Shares will have been duly authorized by all necessary corporate action of the Company, and the Shares will be validly issued, fully paid and nonassessable.

May 20, 2010
Page 2

     This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act. We consent to your filing this opinion as an exhibit to the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Latham & Watkins