A transient current in a rectifier circuit is effectively reduced. In a rectifier circuit, a first rectifier is provided between a first terminal and a second terminal. In the rectifier circuit, when a switch element is turned ON, a primary winding current flows from a power supply to a primary winding of a transformer. When the switch element is turned OFF, a second rectifier current flows from a secondary winding of the transformer to a second rectifier. During a period in which the second rectifier current is flowing, a reverse voltage is applied between the first terminal and the second terminal.