In a semiconductor apparatus in which a main current of a semiconductor device flows through a wiring pattern formed on an insulation circuit board, the rise in temperature of the wiring pattern is suppressed and the increase in cost of parts can be minimized. On the insulation circuit board, a copper pattern is formed. A heat spreader is soldered to the copper pattern, and the heat spreader is loaded with a semiconductor chip. An external electrode and the heat spreader are arranged to shorten the distance between the side of the external electrode and the side of the heat spreader.