A motor includes a frame in the shape of a bottomed cylinder, a stator housed in the frame, a rotor, an end plate for closing an opening of the frame, and bearings rotatably supporting a rotary shaft of the rotor. The frame has, on its bottom, a bearing holder at the center and ribs extending like rays from the bearing holder radially outward and protruding to the inside of the frame. Each rib has a radially outer end reaching a circumferential wall of the frame.