The rectifier includes a rectification MOSFET; a comparator having the non-inverted input terminal connected to a drain of the rectification MOSFET and the inverted input terminal connected to a source of the rectification MOSFET, and the control circuit controlling ON and OFF of the rectification MOSFET by an output of the comparator. The control circuit includes the shutoff MOSFET for performing shutoff between the drain of the rectification MOSFET and the non-inverted input terminal of the comparator and the shutoff control circuit performing electrical shutoff between the drain of the rectification MOSFET and the non-inverted input terminal of the comparator by turning off the shutoff MOSFET when a voltage of the drain of the rectification MOSFET is equal to or higher than a first predetermined voltage.