A semiconductor device includes a semiconductor chip generating heat, a pair of heat sinks, which face each other, to conduct heat from both surfaces of the chip, a pair of compressible insulating sheets, and a mold resin covering the chip, the heat sinks, and the sheets such that the sheets are exposed from the surface of the resin. The mold resin is prevented from covering the outer surfaces of the heat sinks, which are pressed by mold parts, and breakage of the chip is avoided during molding. The plates are insulated by the sheets, so no dedicated insulating sheets for the heat sinks are needed after the device is completed.