An inverter unit is provided with: a case for housing a circuit board on which switching elements, diodes, and a capacitor are mounted; and a heat sink constructed integrally with the case. The inverter unit is mounted to an upper portion of the rotary electric machine by fixing the case to a mounting plate mounted to a boss. In addition, the inverter unit is electrically connected to three phase output terminals projecting out of a rear bracket by means of alternating-current wiring, and is electrically connected to a battery by means of direct-current wiring.