EXHIBIT 32.1

                           ULTRA CLEAN HOLDINGS, INC.
                  SARBANES-OXLEY ACT SECTION 906 CERTIFICATION

The certification set forth below is being submitted in connection with the
quarterly report on Form 10-Q of Ultra Clean Holdings, Inc. for the quarter
ended September 30, 2004 (the "Report") for the purpose of complying with Rule
13a-14(b) or Rule 15d-14(b) of the Securities Exchange Act of 1934 (the
"Exchange Act") and Section 1350 of Chapter 63 of Title 18 of the United Code.

1.    the Report fully complies with the requirements of Section 13(a) or 15(d)
      of the Exchange Act; and

2.    the information contained in the Report fairly presents, in all material
      respects, the financial condition and results of operations of Ultra Clean
      Holdings, Inc.

Date: November 08, 2004

                                                     /s/ Clarence L. Granger
                                                -------------------------------
                                                       Clarence L. Granger
                                                     Chief Executive Officer