The method of producing a semiconductor device in which chips are resin-molded, including steps of: preparing frames having front and back surfaces and die pads; preparing an insulation resin sheet having a first and a second surfaces; preparing a resin-sealing metal mold having cap pins; mounting the resin sheet inside the resin-sealing metal mold in such a manner that the second surface of the resin sheet contacts an inner bottom surface of the resin-sealing metal mold; mounting power chips on the surfaces of the die pads; positioning the frames on the first surface of the resin sheet in such a manner that the back surfaces of the die pads contact the first surface of the resin sheet; pressing the die pads toward the resin sheet using the cap pins and fixing the die pads; injecting a sealing resin in the resin-sealing metal mold and hardening the sealing resin; and removing the semiconductor device in which the power chips are molded with the sealing resin out from the resin-sealing metal mold. The resin sheet may include a metal foil which is disposed to the second surface.