A ring-shaped P⁺ type diffusion region is formed on the top surface of a P type substrate in such a way as to surround a single internal circuit region. A shunt wiring is formed in an area including directly above the P⁺ type diffusion region on the P type substrate. The shunt wiring is connected to the P⁺ type diffusion region by a plurality of contacts. The shunt wiring is provided with an annular ring portion surrounding the internal circuit region. A meander inductor led out from the ring portion and the one end of the meander inductor is connected to a ground potential wiring. A resonance circuit is formed by a parasitic capacitor and the inductance of the shunt wiring. The parasitic capacitor is formed between the shunt wiring and the P⁺ type diffusion region on the P type substrate.