A first circuit and a second circuit, which have different operating voltages, are connected through a level shifter, and a combination circuit below is provided in the level shifter. An enable signal, which is switched between active and inactive states according to whether or not a potential is supplied to a second high potential power line, is applied to the combination circuit. The combination circuit outputs a first signal and a second signal, which is acquired by logically inverting the first signal, to a level shift circuit according to an output signal of the first circuit, in a case where the enable signal is active, and causes both the first signal and the second signal to be at a low level in a case where the enable signal is inactive.