A brush holder is placed between a yoke housing and a gear housing and includes a holder member and a base member. The holder member is installed to an opening of the yoke housing and holds a plurality of brushes. The base member is installed to the holder member and includes a connector, which is adapted to connect with an external connector to receive an electric power. An output side end part of the yoke housing has a flange portion, through which the gear housing is fixed to the yoke housing. The holder member includes a contact portion that contacts the flange portion of the yoke housing in an axial direction of a rotatable shaft.