Abstract: A DC/DC converter is constituted of a switching element (e.g., a MOS transistor), an LC low-pass filter constituted of an inductor and a capacitor, and a control circuit for controlling the on/off timing of the switching element such that the output voltage is set to a predetermined voltage value. A series circuit (serving as a snubber circuit) constituted of a resistor and a switch is further connected in parallel with the inductor. The control circuit closes the switch so that the resistor is connected in parallel with the inductor in a resonance mode of the LC low-pass filter. Thus, it is possible to dissipate energy accumulated in the inductor in a short time without using a relatively large circuit scale, thus avoiding the occurrence of ringing.