MENLO PARK, CA, JANUARY 24, 2007 — Ultra Clean Holdings, Inc. (NASDAQ: UCTT), the parent company of Ultra Clean Technology (UCT), a leading developer and supplier of critical subsystems for the semiconductor capital equipment and advanced medical device industries, announced today that it has completed a planned transitional phase following their acquisition of Sieger Engineering, Inc. At the time of acquisition, Sieger Engineering, Inc. was a manufacturer of precision subsystems for the semiconductor, flat panel and medical capital equipment industries. The objective of this transition was to fully integrate the capabilities of Sieger into UCT and to provide added value to new and existing Sieger customers on an on-going basis.

New, Value Added Capabilities
UCT will now offer medical device manufacturers an expanded resource for high precision electromechanical assemblies and highly complex, machined sub-assemblies. This unique offering builds on UCT's cutting-edge experience in semiconductor subsystems manufacturing. UCT's world class semiconductor experience combined with highly specialized manufacturing capabilities results in a proven resource for those companies seeking to outsource the manufacture of critical medical device subsystems.

Complex Medical Device Modules and Subsystems
UCT currently provides Sunnyvale, CA-based Intuitive Surgical® (Nasdaq: ISRG) with critical components for advanced surgical robots. These unique assemblies are high precision, complex electromechanical components used in the innovative da Vinci® Surgical System. Intuitive Surgical's da Vinci® Surgical System offers surgeons superior visualization, enhanced dexterity, greater precision and ergonomic comfort for the optimal performance of minimally invasive surgery. There are 509 of these robotic systems in use globally and UCT provides the majority of the 3-arm and 4-arm robotic modules.

One of the key benefits of working with UCT is the understanding of and compliance with strict FDA regulations. Another consideration is the ability to fabricate a variety of complex parts at extremely tight tolerances. Also critical is UCT's extensive metallurgical knowledge and technical experience at the foundry level which results in superior castings and ultimately better finished products.

About Ultra Clean Holdings, Inc.
Ultra Clean Holdings, Inc. is a developer and supplier of critical subsystems for the semiconductor capital equipment and medical device manufacturing industries. Ultra Clean offers its customers a complete outsourced solution for a wide variety of complex modules ranging from liquid and gas delivery systems to robotic device assemblies. The company can facilitate improved design-to-delivery cycle times and enable their customers to focus on R&D, product development and other core competencies. Ultra Clean's customers are primarily original equipment manufacturers of semiconductor capital equipment and complex medical devices. The Company is headquartered in Menlo Park, California with facilities in South San Francisco, Portland, Austin and Shanghai, China. Additional information is available at www.uct.com.

About Intuitive Surgical, Inc.
Intuitive Surgical, Inc. is the global leader in the rapidly emerging field of robotic-assisted minimally invasive surgery. Since its inception, the company has consistently provided surgeons and hospitals with the tools needed to improve clinical outcomes and to help patients return to active and productive lives. With its corporate headquarters located in Sunnyvale, California, Intuitive Surgical serves customers throughout the United States and internationally, providing technology and procedural innovation across cardiac, urology, gynecologic, pediatric and general surgical disciplines.