Abstract: A DC-DC converter includes an inductor device with an inductance value that is switched between a first inductance and a second inductance larger than the first inductance in a case where a load includes a first load and a second load heavier than the first load and a switching circuit electrically connected to the inductor device. The inductor device includes a first coil, a second coil, and a switching element with a resistance value that is controlled in accordance with the load. A circuit in which the second coil and the switching element are electrically connected in series and the first coil are electrically connected in parallel.