MENLO PARK, CA, March 28, 2005 — Ultra Clean Holdings, Inc. (Nasdaq: UCTT), a developer and supplier of critical subsystems for the semiconductor capital equipment industry, today announced the grand opening of Ultra Clean Technology’s (UCT) new manufacturing plant in Shanghai, China.  Located in the Kangqiao Industrial Zone, Pudong, Shanghai, the 52,000 square foot facility, includes 5,500 square feet dedicated to Class 100 and Class 1000 cleanrooms plus an additional 30,000 square feet of warehouse space to facilitate future expansion. The company has additional manufacturing facilities in Menlo Park, CA (Corporate Headquarters); Austin, TX and a facility in Tualatin, OR near Portland.

The grand opening reception and traditional ribbon-cutting ceremonies were held on March 18 and were presided over by UCT’s president and chief executive officer, Clarence Granger. Guests of note that attended the ribbon-cutting included: Mr. Dong Tao, Assistant Director and Supervisor of the Overseas Department of Shanghai Municipal Foreign Investment Development Board; Mr. Sheng Baoshan, Vice Director of Administration Commission of Kangqiao Industrial Zone; Mr. Pan Xiangsheng, Deputy General Manager of Kangqiao Industrial Zone and Mr. Keith Cheung, Managing Director of UCT China. After the ceremony, guests enjoyed an opportunity to tour the facility.

Following the opening ceremonies, a banquet was held at the St. Regis Hotel featuring the introduction of guests. Keynote speeches were presented by Mr. Clarence Granger, Mr. Yu Jianming, Deputy Secretary General of Shanghai Foreign Economic Relations and Trade Commission and Mr. Chen Ce, Secretary of CPC Nanhui District Committee. As part of his comments, Mr. Granger noted, "It was clear to us that to capture additional outsourcing opportunities in the semiconductor subassembly manufacturing and integration business, we needed to locate where those opportunities currently exist and are likely to expand. We believe that opening this facility in Shanghai will allow us to serve current customers more effectively and position our company favorably for developing  new customers in the Asia Pacific market."

About the New Facility
The UCT China facility is devoted to the manufacture of gas delivery systems and other major modules and subsystems found in semiconductor process tools. The Shanghai facility, which opened its doors in November 2004 and shipped its first product on February 4, 2005 following an extensive manufacturing training program. Approximately 45 employees are currently on staff in manufacturing, materials, quality assurance, and general administration positions. Preparations for ISO Certification commenced in January 2005.  ISO 9000:2000 Certification for this new facility is anticipated in Q3 2005.

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.

Safe Harbor Statement
The foregoing information 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 our current views with respect to future events.  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 our S-1 registration statement and Form 10-Q's filed with the Securities and Exchange Commission. Ultra Clean Holdings, Inc. undertakes no obligation to publicly update or review any forward-looking statements, whether as a result of new information, future developments or otherwise.