A semiconductor device includes: a resin case that houses a semiconductor element; a parallel plate that is disposed inside the resin case while being connected with the semiconductor element, the parallel plate including two flat plates parallel to each other with an insulating material therebetween; two electrodes that are each led out from two electrode lead-out portions in an upper end of the parallel plate and are disposed on an upper surface of the resin case at a predetermined interval; and a metal plate that stands erect on the main surface of the flat plate in a region at the predetermined interval between the two electrode lead-out portions.