Provided is a semiconductor device capable of improving heat-radiating performance of a heating element. The semiconductor device of the present invention includes: a heating element (1); a heat-radiating member (2) including an element contact portion (2a) which is held surface contact with a mounting surface (1e); a first pressing member (3) and a second pressing member (4) held in contact with the heating element (1); and a fixation screw (6) for fixing the first pressing member (3) to the heat-radiating member (2) through a through hole (3c) formed through the first pressing member (3). The first pressing member (3) and the second pressing member (4) each include an inclined surface formed so that a component force of an axial force of a tightening force of the fixation screw (6) is generated in a vertical direction with respect to the mounting surface (1e).