EXHIBIT 32.2

CERTIFICATION

PURSUANT TO

18 U.S.C. SECTION 1350

As Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

The undersigned, Ilan Daskal, the Chief Financial Officer of International Rectifier Corporation (the “Company”), pursuant to 18 U.S.C. §1350, hereby certifies that:

(i) the Annual Report on Form 10-K of the Company for the fiscal year ended June 26, 2011 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(ii) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: August 22, 2011

/s/ ILAN DASKAL

Ilan Daskal

Chief Financial Officer

(Principal Financial and

Accounting Officer)