A motor includes a rotation shaft, a commutator, power supply brushes, and a brush holder. The brush holder includes an opposing portion that faces an end face of the commutator in an axial direction, a bearing holder, and a diffusion stopper. The diffusion stopper is arranged in a portion of the opposing portion located toward the outer side in the radial direction from the bearing holder and limits the diffusion of abrasion powder of the power supply brushes. The diffusion stopper is projected toward the commutator in the axial direction or recessed in the axial direction.