A high-speed, high-reliability semiconductor device is provided by forming an interlayer insulation film which can rapidly transmit the heat generated in wiring and is low in the capacity of wiring. The semiconductor device comprises a conductive substrate and low-resistance multi-layer wiring of a metal or the like, laminated through a first insulator onto the top surface and/or the back surface of the conductive substrate, characterized in that a through hole is provided in the first insulator between the low-resistance wirings and the through hole comprises at least a hole filled with a conductor (through hole: TH) and a hole filled with a second insulator having a larger thermal conductivity than the first insulator (dummy hole: DH). Furhter, it is characterized in that the same TH and DH are provided also between the low-resistance wiring and the conductive substrate or between the uppermost low-resistance wiring and a heat radiator.
