A method for manufacturing a semiconductor module, includes the steps of preparing a board; mounting a semiconductor device on the second metal foil; placing a resin case onto the board for surrounding a first metal foil, an insulating sheet, the second metal foil, and the semiconductor device; pouring a resin in a paste form into the case to fill a space relative to the first metal foil, insulating sheet, the second metal foil and the semiconductor device; and heat-curing the resin. A bottom end of a peripheral wall of the case is located above a bottom surface of the first metal. The bottom surface of the first metal foil and the resin form a flat bottom surface to contact an external mounting member.