To provide a level shifter circuit for preventing the generation of through-currents to be generated when the potential of a circuit at an input side is not applied in the power-down and for realizing further low power consumption as for a level shifter circuit for converting a signal between circuits of which potentials are different.

This level shifter circuit is provided with an input part 1 which inputs signals changing between a first ground potential and a first power source, and an output part 2 which voltage-converts signals changing between the first ground potential which obtains the output signal of the input part 1 as an input signal and a second power source, and outputs the signals. In this case, the output part 2 is provided with a means 100 which interrupts the second power source. This level shifter is also provided with a potential detecting circuit 3 which generates a control signal 39 for controlling the interrupting means 100.