An inverter has a plurality of switching elements, the states of which are each switched by a pulse signal supplied in accordance with a power grid voltage. The inverter is provided with: a switching circuit that converts an input DC voltage to an AC voltage and outputs the AC voltage to a pair of output lines; a filter circuit having output coils inserted in the output lines; a current detection sensor that detects the current flowing through the output coils; and a high-speed pulse control circuit that, when an absolute value of the detected current is a threshold value or more, stops the supply of the pulse signal to the switching circuit.