A semiconductor device may include: a semiconductor module in which a semiconductor element is sealed in a resin package, and a heat sink is located on at least one surface of the resin package; an insulating sheet covering the heat sink; a cooling plate which is constituted of resin containing heat transfer fillers, the cooling plate having one surface and another surface, wherein the one surface covers the insulating sheet and is bonded to the at least one surface of the resin package, the other surface is provided with fins; and a cooler constituted of resin and configured to flow coolant along the fins, wherein the cooler surrounds the cooling plate in a view along a normal direction of the cooling plate, and is bonded to both ends of the resin package in the view along the normal direction.