EXHIBIT 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements of 3M Company on Form S-8 (Registration Nos. 33-14791, 33-49842, 33-58767, 333-26957, 333-30689, 333-30691, 333-44760, 333-44692, 333-73192, 333-101727, 333-101751 and 333-109282), and Form S-3 (Registration Nos. 33-48089, 333-42660, 333-98163, 333-109211 and 333-112563), of our report dated February 14, 2005, except as to Notes 3, 16 and 17, for which the date is September 7, 2005, relating to the consolidated financial statements, management’s assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting, which appears in this Current Report on Form 8-K.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Minneapolis, Minnesota

September 7, 2005