A motor and a brush device are provided which allow an easy assembly of brush holders. The brush holders have fixing portions and brush accommodating portions integrally formed therewith. The fixing portions are secured to the gear case, and the brush accommodating portions slidably hold brushes. The motor has a gear case which is integrally formed with a reduction mechanism accommodating portion to accommodate a reduction mechanism and with a brush holder mounting portion in which the brush holders can be installed in a direction of an axis of the output shaft.