A clamp circuit includes a first MOS transistor and a second MOS transistor connected in series with the first MOS transistor. The first MOS transistor has a gate connected to a drain of the first MOS transistor. The second MOS transistor has a gate connected to a drain of the second MOS transistor. The clamp circuit is configured so that at least one of the first MOS transistor and the second MOS transistor causes a body effect.