An opening of a yoke provided to an electric motor is closed by a brush holder of an electricity supply unit. A pair of electricity supply terminals connected to respective brushes is fixed on the brush holder by outsert molding. A brush-side fixing pillar is inserted into a caulking hole piercing through a pigtail connecting portion of each electricity supply terminal, an input-side fixing pillar is inserted into a fixing hole piercing through an input-side connecting portion, and then the brush-side fixing pillar and the input-side fixing pillar are thermally caulked, whereby each electricity supply terminal is fixed on the brush holder. Each input-side fixing pillar and the corresponding brush-side fixing pillar, provided on the brush holder, are spaced away from each other by a predetermined distance so that a first terminal, a second terminal and a choke coil connected therebetween is attachable in place of the electricity supply terminal.