An electronic control unit (50, 70) including semiconductor modules (501 to 506) and capacitors (701 to 706) is disposed in the axial direction of a motor (30). The semiconductor modules (501 to 506) are placed longitudinally and brought into contact with a heat sink (601). The vertical line to each of surfaces of semiconductor chips included in the semiconductor modules (501 to 506) is perpendicular to the axial line of the motor (30). Accordingly, the capacitors (701 to 706) are disposed so that at least a part of the capacitors (701 to 706) overlap the semiconductor modules (501 to 506) and heat sink (601) in the axial direction of the motor (30).