ACM Research Inc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to

Section 14(a) of the Securities Exchange Act of 1934

Check the appropriate box:

ACM Research, Inc.

(Name of Registrant as Specified In Its Charter)

Payment of Filing Fee (Check the appropriate box):

NOTICE OF

2025 ANNUAL MEETING

OF STOCKHOLDERS

and

PROXY STATEMENT

42307 Osgood Rd, Suite IFremont, California 94539

April 29, 2025

Dear Fellow Stockholder:

It is my pleasure to invite you to attend the Annual Meeting of Stockholders of ACM Research, Inc. to be held on June 12, 2025, at 7 a.m., Pacific time. This year’s Annual Meeting will be a “virtual meeting” conducted via live audio webcast, consistent with our prior practice. Each holder of Class A or Class B common stock as of 5 p.m., Eastern time, on the record date of April 15, 2025, will be able to participate in the Annual Meeting by accessing a live webcast atvirtualshareholdermeeting.com/ACMR2025 and entering the control number included on the stockholder’s Notice of Internet Availability of Proxy Materials or proxy card. Stockholders will also be able to vote their shares and submit questions via the Internet during the meeting by participating in the webcast.

During the Annual Meeting, stockholders will be asked to elect the entire board of directors and to ratify the appointment of Ernst & Young Hua Ming LLP as our independent auditor for 2025.

We are furnishing proxy materials to our stockholders over the Internet. This process expedites the delivery of proxy materials to our stockholders, lowers our costs and reduces the environmental impact of the Annual Meeting. Today we are sending to each of our stockholders a Notice of Internet Availability of Proxy Materials containing instructions on how to access our Proxy Statement for the Annual Meeting and our 2024 Annual Report to Stockholders, as well as how to vote via proxy either by telephone or over the Internet.

It is important that you vote your shares of Class A and Class B common stock virtually or by proxy, regardless of the number of shares you own. You will find the instructions for voting on your Notice of Internet Availability of Proxy Materials or proxy card. We appreciate your prompt attention.

The board invites you to participate in the Annual Meeting so that management can listen to your suggestions, answer your questions, and discuss business developments and trends with you. Thank you for your support, and we look forward to joining you at the Annual Meeting.

Sincerely,

David H. Wang

Chief Executive Officer and President

NOTICE OF2025 ANNUAL MEETING OF STOCKHOLDERS

To Stockholders of ACM Research, Inc.:

The board of directors is soliciting proxies for use at the ACM Research, Inc. 2025 Annual Meeting of Stockholders. You are receiving the enclosed proxy statement because you were a holder of Class A or Class B common stock as of 5 p.m., Eastern time, on the record date of April 15, 2025 and therefore are entitled to vote at the Annual Meeting.

You may participate in the Annual Meeting, including casting votes and submitting questions, by accessing a live webcast atvirtualshareholdermeeting.com/ACMR2025 and then using the 16-digit control number provided on the Notice of Internet Availability of Proxy Materials or proxy card being delivered to you. Online check-in to the Annual Meeting will begin at 6:45 a.m., Pacific time, and stockholders are encouraged to allow time to log in to the meeting webcast and test their computer audio system. There will be no physical location for the Annual Meeting.

The Annual Meeting will be held to consider and vote upon the following proposals:

In addition, any other business properly presented may be acted upon at the Annual Meeting. Each share of Class A common stock is entitled to one vote, and each share of Class B common stock is entitled to twenty votes for each proposal.

In accordance with Securities and Exchange Commission rules, we are providing stockholders with access to proxy materials on the Internet, instead of mailing printed copies. We are mailing to stockholders, commencing on or about April 29, 2025, a Notice of Internet Availability of Proxy Materials to provide:

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON June 12, 2025:The Notice of 2025 Annual Meeting of Stockholders, the Proxy Statement, the 2024 Annual Report to Stockholders and instructions for voting via the Internet can be accessed at proxyvote.com.

How to Vote in AdvanceYour vote is important. Please vote as soon as possible by one of the methods shown below. Your Notice of Internet Availability of Proxy Materials, proxy card or voting instruction form should be readily available.Via Internet (Any Web-Enabled Device) By Telephone (U.S. or Canada only) By Mail (Pursuant to Printed Materials) We will maintain a list of stockholders of record as of the record date at our corporate headquarters located at 42307 Osgood Road, Suite I, Fremont, California 94539 for a period of ten days prior to, and ending at the close of, the Annual Meeting. In order for us to make the list available to you quickly and safety, we recommend that you notify us by emailing investor.relations@acmr.com one business day in advance of the day on which you intend to review the list. Beginning fifteen minutes prior to, and ending at the close of, the Annual Meeting, the list of our stockholders of record will be available for viewing by stockholders for any purpose germane to the meeting at virtualshareholdermeeting.com/ACMR2025.

42307 Osgood Rd, Suite IFremont, California 94539

Proxy Statement dated April 29, 2025

2025 Annual Meeting of Stockholders

ACM Research, Inc., a Delaware corporation, is furnishing this Proxy Statement and related proxy materials in connection with the solicitation by its board of directors of proxies to be voted at its 2025 Annual Meeting of Stockholders and any adjournments. ACM Research, Inc. is providing these materials to the holders of record of its Class A common stock, $0.0001 par value per share, and Class B common stock, $0.0001 par value per share, as of 5 p.m., Eastern time, on the record date of April 15, 2025 and is first mailing the materials on or about April 29, 2025.

Your vote is important.

Please see the detailed information that follows in the Proxy Statement.

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