A rotating electrical machine for a vehicle includes a protective cover including a protruding portion projected to an opening side from a circumferential edge portion of a through hole formed in a bottom portion, a stud bolt that is inserted into the through hole to fix a rectifier to a portion of a casing at a position on one side in an axial direction, a mold resin including a projecting portion projected toward the protective cover, for electrically insulating the rectifier and the stud bolt from each other, and a fitting fixed to an extending portion of the stud bolt that extends from the through hole. A harness clamp is held by the fitting, and the projecting portion and the protruding portion are arranged at a position so that the projecting portion and the protruding portion are overlapped with each other in the axial direction of the stud bolt.