A semiconductor substrate includes a via-hole that extends from a first surface to a second surface. An electrode pad layer that serves as the bottom of the via-hole is disposed on the second surface. An insulating layer is formed on the first surface of the semiconductor substrate and the sidewall of the via-hole. A metal layer is formed on the first surface of the semiconductor substrate and the sidewall of the via-hole with the insulating layer interposed therebetween and is directly formed on the bottom of the via-hole. An inclined surface is formed on the sidewall of the via-hole such that the bottom of the via-hole has a smaller opening size than the open end of the via-hole. The inclined surface has asperities.