PURPOSE: To completely interrupt the current caused to flow by a control signal regardless of the circuitry to be connected to an output terminal by providing a first to a third switching circuits.

CONSTITUTION: A control circuit interrupts the current flowing to a level shift circuit 33 according to a control signal, and the first switching circuit interrupts the current flowing to either transistors M8 or M9 which constitute a source grounded amplifier circuit 34. The second switching circuit also interrupts the current flowing between the level shift circuit 33 and the source grounded amplifier circuit 34, and the third switching circuit interrupts the current flowing to the rest of the transistors M9 or M8 which constitute the source grounded amplifier circuit 34.