A semiconductor device includes a semiconductor substrate, a first lower-layer line for supplying power to a transistor formed on the semiconductor substrate, a first interlayer line which is connected to the first lower-layer line, and an allowable current of which is larger than that of the first lower-layer line; and an upper-layer line which is provided above the first interlayer line and receives power input from outside. The first interlayer line is connected to the upper-layer line through a switch circuit formed on the semiconductor substrate.