A semiconductor device in which a semiconductor chip 1 is bonded by a metal bond 2 to one surface of a heat sink 4 formed of a material with a thermal expansion coefficient is close to he semiconductor chip 1, the heat sink 4 is glued to a stiffener with a silicon adhesive 5 with an elastic modulus of 10 MPa or less, a TAB tape 9 is glued to the stiffener 3 with an epoxy adhesive 6, and the semiconductor chip 1 is sealed with an epoxy sealing resin 8 with an elastic modulus of 10 GPa or more for protection from outside.