The semiconductor device of the present invention includes a first conductive type semiconductor layer; a second conductive type source region formed in a surface layer portion of the semiconductor layer; a groove formed by digging in the source region from a surface thereof; an insulating film laminated on the semiconductor layer to cover a surface of the semiconductor layer; a contact hole penetrating through the insulating film in a layer thickness direction at least at a position facing the groove; a wiring formed on the insulating film; and a contact plug embedded in the contact hole so that a bottom portion thereof enters the groove to electrically connect the wiring and the source.