An oscillation circuit according to the present invention comprises a solid-state oscillator, an amplifier for feedback-controlling the solid-state oscillator, and ESD protecting circuits respectively connected to the input and output sides of the amplifier, wherein the ESD protecting circuit on the input side of the amplifier comprises an ESD protecting element whose constituent is a diode having a P-type diffusion layer and an N-type diffusion layer, and the ESD protecting circuit on the output side of the amplifier comprises an ESD protecting element whose constituent is an MOS transistor.