To improve the connection reliability of a module solder bonding a heat spreader on the main electrode surface of a semiconductor chip, and connecting a lead via the heat spreader.

The semiconductor device has such a structure that the heat spreader 7 which also serves for an electrode plate is brazed (soldered) to the upper-side main electrode surface of the semiconductor chip 3 mounted on an insulation substrate 2 and the wiring lead 4 is connected to the top face of the heat spreader. The heat spreader consists of a metal base material 7a (copper or aluminum), and a different species metal film 7b (Ni, Ni-P, Ni-P/Au plating film, etc.) is formed on one surface of the metal base material 7a to increase the adhesion with a brazing material (solder). The surface of the heat spreader which is formed with the different species metal film 7b is brazed to the semiconductor chip, and the wiring lead 4 made of the same kind of metal as the base material of the heat spreader is directly bonded (for example, by ultrasonic bonding) to the other surface of the heat spreader as a lead member.