PURPOSE: To provide a semiconductor device wherein the heat resistance of the bonding part of a semiconductor chip to a ceramic insulator is small and it is possible to prevent the semiconductor chip from being damaged by a fire.

CONSTITUTION: A bonding layer between a ceramic insulator 14 and a semiconductor chip 15 before a soldering operation is constituted in the following manner: a metallized layer 20 is formed on the ceramic insulator 14; and plated layers in the order of a nickel-plated layer 22 and a gold-plated layer 24 are formed on its surface. Rear metals for the semiconductor chip 15 are arranged and installed in the order of a vanadium layer 26, a nickel layer 27 and a gold layer 28 from the part close to the semiconductor chip 15. The thickness of the nickel layer 27 is set at 1000 to 2000. A gold-germanium-antimony solder 16 is sandwiched between the gold-plated layer 24 and the gold layer 28.