According to an embodiment, a semiconductor integrated circuit includes a regulator, a level shifter and a switch circuit. The regulator converts an input voltage that is a difference in potential between a first terminal and a third terminal into an output voltage that is a difference in potential between a second terminal and the third terminal. The level shifter adjusts a voltage level between a first terminal and a second terminal. The switch circuit includes a first switch selectively connecting the third terminal of the regulator to a first potential, a second switch selectively connecting the third terminal of the regulator to the first terminal of the level shifter, and a third switch selectively connecting the third terminal of the regulator to a second potential.