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Press Release Exhibit 99.1 Source : Ultra Clean Holdings , Inc. Ultra Clean Reports Third Quarter 2021 Financial Results HAYWARD , Calif . , October 27 , 2021 / PRNewswire / Ultra Clean Holdings , Inc. ( Nasdaq : UCTT ) , today reported its financial results for the third quarter ended September 24 , 2021 . " UCT's third quarter performance and fourth quarter outlook demonstrate strong execution in a demanding environment across our end markets , " said Jim Scholhamer , CEO . " UCT's operational and supply chain flexibility has proven to be advantageous in meeting customer demand . Ongoing , targeted investments in our business will expand our global capacity and position us well for sustainable growth . ” Third Quarter 2021 GAAP Financial Results Total revenue was $ 553.7 million . Products contributed $ 482.0 million and Services added $ 71.7 million . Total gross margin was 20.6 % , operating margin was 9.1 % , and net income was $ 31.9 million or $ 0.71 and $ 0.70 per basic and diluted share . This compares to total revenue of $ 515.2 million , gross margin of 19.4 % , operating margin of 6.2 % , and net income of $ 17.1 million or $ 0.39 per basic and diluted share in the prior quarter . Third Quarter 2021 Non - GAAP Financial Results On a non - GAAP basis , gross margin was 21.6 % , operating margin was 12.4 % , and net income was $ 48.8 million or $ 1.07 per diluted share . This compares to gross margin of 21.2 % , operating margin of 11.7 % , and net income of $ 43.7 million or $ 0.99 per diluted share in the prior quarter . Fourth Quarter 2021 Outlook The Company expects revenue in the range of $ 590.0 million to $ 630.0 million and GAAP diluted net income per share to be between $ 0.89 and $ 1.06 . The Company expects non - GAAP diluted net income per share to be between $ 1.12 and $ 1.29 . Conference Call The call will take place at 1:45 p.m. PT and can be accessed by dialing 1-844-826-3034 or 1-412-317-5179 . No passcode is required . A replay of the call will be available by dialing 1-877-344-7529 or 1-412-317-0088 and entering the confirmation code 10160642. The Webcast will be available on the Investor Relations section of the Company's website at http://uct.com/investors/events/ . About Ultra Clean Holdings , Inc. Ultra Clean Holdings , Inc. is a leading developer and supplier of critical subsystems , components and parts , and ultra - high purity cleaning and analytical services primarily for the semiconductor industry . Under its Products division , UCT offers its customers an integrated outsourced solution for major subassemblies , improved design - to - delivery cycle times , design for manufacturability , prototyping , and high - precision manufacturing . Under its Services Division , UCT offers its customers tool chamber parts cleaning and coating , as well as micro - contamination analytical services . Ultra Clean is headquartered in Hayward , California . Additional information is available at www.uct.com . Use of Non - GAAP Measures In addition to providing results that are determined in accordance with Generally Accepted Accounting Principles in the United States of America ( GAAP ) , management uses non - GAAP gross margin , non - GAAP operating margin and non - GAAP net income to evaluate the Company's operating and financial results . We believe the presentation of non - GAAP results is useful to investors for analyzing our core business and business trends and comparing performance to prior periods , along with enhancing investors ' ability to view the Company's results from management's perspective . The presentation of this additional information should not be considered a substitute for results prepared in accordance with