Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

The Board of Directors

Cymer, Inc.:

We consent to the incorporation by reference in the registration statements (No. 333-16559, No. 333-99975, No. 333-88616, No. 333-67491, No. 333-48242, No. 333-69736, No. 333-109544, No. 333-118496, No. 333-127748, No. 333-142621, No. 333-145089, and 333-160995) on Form S-8 of Cymer, Inc. of our reports dated February 18, 2011, with respect to the consolidated balance sheets of Cymer, Inc. and subsidiaries as of December 31, 2010 and 2009, and the related consolidated statements of operations, comprehensive income, equity, and cash flows, for each of the years in the three-year period ended December 31, 2010, and the related consolidated financial statement schedule, and the effectiveness of internal control over financial reporting as of December 31, 2010, which reports appear in the December 31, 2010 annual report on Form 10-K of Cymer, Inc.

/s/ KPMG LLP

San Diego, California

February 18, 2011