A semiconductor device including: an insulating circuit substrate including a principal surface and a back surface; semiconductor chips each including an electrode on a principal surface and having a back surface on an opposite side to the principal surface, the back surface being fixed to the principal surface of the insulating circuit substrate; a wiring substrate facing the principal surface side of the insulating circuit substrate, separated from the semiconductor chip; a conductive post fixed to the electrode of the semiconductor chips and the wiring substrate; and a resin sealing body sealing the insulating circuit substrate, the semiconductor chips, the wiring substrate, and the conductive posts in such a manner as to expose the back surface of the insulating circuit substrate, wherein the semiconductor chips are respectively arranged on sides on which two short sides are located, and the conductive post has a recessed portion on its peripheral surface.