The purpose of the present invention is to provide a semiconductor device which has more improved reliability in terms of thermal stress. A semiconductor device according to the present invention is provided with an insulating layer (32), a conductive layer (33) that is bonded to one main surface of the insulating layer (32), and a semiconductor element (1) that is arranged so that the upper surface thereof faces the same direction as the one main surface of the insulating layer (32); and the upper surface of the semiconductor element (1) is provided with an upper electrode (9). The semiconductor device is additionally provided with: a wiring member (4) which has one end electrically connected to the upper electrode (9) of the semiconductor element (1) and the other end electrically connected to the conductive layer (33), while having a hollow portion (4a); a first sealing material (71); and a second sealing material (72) that is softer than the first sealing material (71). The first sealing material (71) seals at least a part of the semiconductor element (1) so as to be in contact with the semiconductor element (1); and the second sealing material (72) seals the wiring member (4)so as to be in contact with the wiring member (4).