Exhibit 5.1

[Letterhead of Gibson, Dunn & Crutcher LLP]

January 29, 2009

Adept Technology, Inc.

5960 Inglewood Drive

Pleasanton, California 94588

Re: Adept Technology, Inc./Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as counsel to Adept Technology, Inc., a Delaware corporation (the “Company”), in connection with the preparation of that certain registration statement on Form S-3 (the “Registration Statement”) to be filed with the Securities and Exchange Commission (the “SEC”) on the date hereof, with respect to up to 141,922 shares of the Company’s common stock, par value $0.001 per share (the “Shares”), which have been issued to the selling stockholders named in the Registration Statement.

We have examined the originals, or photostatic or certified copies, of such records of the Company and certificates of officers of the Company and of public officials and such other documents as we have deemed relevant and necessary as the basis for the opinions set forth below. In our examination, we have assumed the genuineness of all signatures, the legal capacity and competency of all natural persons, the authenticity of all documents submitted to us as originals and the conformity to original documents of all documents submitted to us as copies.

Based upon the foregoing examination and in reliance thereon, and subject to the assumptions stated and in reliance on statements of fact contained in the documents that we have examined, we are of the opinion that the Shares which have been issued have been duly authorized and are duly and validly issued, fully paid and non-assessable.

We are admitted to practice in the State of California, and are not admitted to practice in the State of Delaware. However, for the limited purposes of our opinion set forth above, we are generally familiar with the Delaware General Corporation Law (the “DGCL”) as presently in effect and have made such inquiries as we consider necessary to render this opinion with respect to a Delaware corporation. This opinion letter is limited to the laws of the State of California and, to the limited extent set forth above, the DGCL, as such laws presently exist and to the facts as they presently exist. We express no opinion with respect to the effect or applicability of the laws of any other jurisdiction. We assume no obligation to revise or supplement this opinion letter should the laws of such jurisdictions be changed after the date hereof by legislative action, judicial decision or otherwise.

We consent to the filing of this opinion as an exhibit to the Registration Statement, and we further consent to the use of our name under the caption “Legal Matters” in the Registration Statement and the prospectus that forms a part thereof. In giving these consents, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the Rules and Regulations of the Securities and Exchange Commission.

Very truly yours,

/s/ Gibson, Dunn & Crutcher LLP