A semiconductor device includes: a base plate; a semiconductor chip mounted on the base plate; a case surrounding the semiconductor chip on the base plate; an electrode terminal connected to the semiconductor chip; a sealing material covering an upper face of the base plate, the semiconductor chip and a part of the electrode terminal in the case; and a lid fastened to the case above the sealing material, wherein the electrode terminal is not exposed on an upper face of the sealing material, and there is a gap between the upper face of the sealing material and a lower face of the lid.