The present invention increases noise immunity of an electrical leakage detection circuit. A first comparator COMP1 generates a first comparison signal indicating a comparison result between a voltage corresponding to a detected signal from a zero-phase-sequence current transformer and a predetermined first threshold voltage VTH1. A judgment circuit outputs a judgment signal indicating if there is electrical leakage based on the first comparison signal and outputs a mask signal corresponding to the first comparison signal. A mask circuit generates a latch input signal based on the judgment signal and the mask signal. An output stage comprises a latch circuit which latches a state of the latch input signal when the latch input signal is asserted. The output stage generates a drive signal corresponding to the state of the latch circuit.