In a DC to DC converter, a transformer circuit includes a primary winding and a secondary winding member composed of series-connected first to fourth secondary windings having one and the other ends. The one and the other ends of the series-connected first to fourth secondary windings are connected to a first output terminal. The first and second secondary windings are wound around a first magnetic path in opposite directions, and the third and fourth secondary windings are wound around a second magnetic path in opposite directions. A first rectifying element is connected between the second output terminal and a connection point between the first and second secondary windings. A second rectifying element is connected between the second output terminal and a connection point between the third and fourth secondary windings.