3M (MMM) 10-K 2007 FY Annual report

EXHIBIT 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (Registration Nos. 33-14791, 33-49842, 33-58763, 33-58767, 333-26957, 333-30689, 333-30691, 333-44760, 333-44692, 333-73192, 333-101727, 333-101751, 333-109282, 333-128251 and 333-130150) and Form S-3 (Registration Nos. 33-48089, 333-42660, 333-98163, 333-109211, 333-112563 and 333-132041) of 3M Company of our report dated February 11, 2008, relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Minneapolis, Minnesota

February 15, 2008