Disclosed is a DC-DC converter including: a first switching element ON/OFF controlling a current fed from a primary side to a secondary side; a second switching element provided in parallel to the first switching element, controlled at a substantially same timing as an ON/OFF timing of the first switching element and being lower in current rating than the first switching element; and a resistance inserted and connected between a node of a primary side of the second switching element and the primary side of the first switching element.