MENLO PARK, CA — (PR Newswire) May 17, 2004 — Ultra Clean Holdings, Inc. (NASDAQ: UCTT), the parent company of Ultra Clean Technology Systems and Service, Inc., announced that Clarence Granger, President and Chief Executive Officer, and Kevin Griffin, Chief Financial Officer, will address the Piper Jaffray Technology Conference in New York, NY, on May 20 at 9:40 am ET.

The presentation can be accessed via webcast at the investor relations section of the Company’s website, www.uct.com, or at http://www.piperjaffray.com/tcwebcast

About Ultra Clean Holdings, Inc.
Ultra Clean Holdings, Inc. is a developer and supplier of critical subsystems for the semiconductor capital equipment industry, focusing on gas delivery systems.  Ultra Clean offers its customers a complete outsourced solution for gas delivery systems, improved design-to-delivery cycle times, component neutral design and manufacturing and component testing capabilities.  Ultra Clean's customers are primarily original equipment manufacturers of semiconductor capital equipment.  The Company is headquartered in Menlo Park, California.  Additional information is available at www.uct.com.