Provided is a semiconductor device comprising a semiconductor substrate that includes a transistor region; an emitter electrode that is provided on the semiconductor substrate; a first dummy trench portion that is provided on the transistor region of the semiconductor substrate and includes a dummy conducting portion that is electrically connected to the emitter electrode; and a first contact portion that is a partial region of the transistor region, provided between an end portion of a long portion of the first dummy trench portion and an end portion of the semiconductor substrate, and electrically connects the emitter electrode and a semiconductor region with a first conductivity type provided in the transistor region.