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

In connection with the quarterly report of Semitool, Inc. (the "Company") on
Form 10-Q for the fiscal quarter ended December 31, 2003 as filed with the
Securities and Exchange Commission (the "Report"), I, Larry A. Viano, Chief
Financial Officer of the Company, hereby certify as of the date hereof, solely
for purposes of Title 18, Chapter 63, Section 1350 of the United States Code,
that to my knowledge:

     (1)  the Report fully complies with the requirements of Section 13(a) or
          15(d), as applicable, of the Securities Exchange Act of 1934, and

     (2)  the information contained in the Report fairly presents, in all
          material respects, the financial condition and results of operations
          of the Company at the dates and for the periods indicated.

A signed original of this written statement required by Section 906, or other
document authenticating the signature that appears in typed form within the
electronic version of this written statement required by Section 906, has been
provided to Semitool, Inc. and will be retained by Semitool, Inc. and furnished
to the Securities and Exchange Commission or its staff upon request.

This Certification has not been, and shall not be deemed, "filed" with the
Securities and Exchange Commission.


Dated:  February 12, 2004         By: /s/Larry A. Viano
                                      ------------------------------------------
                                      Larry A. Viano
                                      Vice President and Chief Financial Officer