In a driving unit of an electromechanical motor unit, a semiconductor chip and a smoothing capacitor are joined to a second main surface of a substrate having a first main surface and the second main surface. The semiconductor chip includes a first end portion facing the second main surface, and a second end portion on the opposite side of the semiconductor chip from the first end portion. The smoothing capacitor includes a third end portion facing the second main surface, and a fourth end portion on the opposite side of the smoothing capacitor from the third end portion. The semiconductor chip is thermally connected to a bottom wall portion of a cover member, at a position closer to the second main surface than the fourth end portion is. The bottom wall portion is thermally connected to the motor housing via a sidewall portion of the cover member.