MENLO PARK, CA, July 12, 2004/PR Newswire — Ultra Clean Holdings, Inc. (Nasdaq: UCTT), the parent company of Ultra Clean Technology Systems and Service, Inc., will release second quarter 2004 financial results on Thursday, July 29, after markets close.

The Company will host a conference call to discuss second quarter 2004 financial results and management’s outlook at 2:00 pm PDT on Thursday, July 29, 2004. The call-in number is 888-722-1090. Additional details will be available on our website at www.uct.com under Investor Relations.  

We will also webcast the conference call live on our website. A telephonic replay of the conference call will be available until 5:00 p.m. PDT on August 12, 2004 on our website at www.uct.com under Investor Relations.

This press release contains, or may be deemed to contain, "forward-looking statements" (as defined in the U.S. Private Securities Litigation Reform Act of 1995) which reflect Ultra Clean Holdings, Inc.’s current views with respect to future events and financial performance.  Ultra Clean Holdings, Inc. uses words such as "anticipates," "believes," "plans," "expects," "future,"' "intends," "may," "will," "should," "estimates," "predicts," "potential," "continue" and similar expressions to identify these forward-looking statements.  All forward-looking statements address matters that involve risks and uncertainties.  Accordingly, you should not rely on forward-looking statements, as there are or will be important factors that could cause our actual results, as well as those of the markets we serve, levels of activity, performance, achievements and prospects to differ materially from the results predicted or implied by these forward-looking statements.  These risks, uncertainties and other factors include, among others, those identified in "Risk Factors," "Management's Discussion and Analysis of Financial Condition and Results of Operations'' and elsewhere in the Company’s S-1.