A power transfer device includes a power transfer coil that transfers power to another device in a non-contact manner, a power transmission and reception circuit that supplies power to the power transfer coil or outputs power received by the power transfer coil to a load circuit, and a protection coil disposed between the power transfer coil and the power transmission and reception circuit to prevent a magnetic flux generated by the power transfer coil from reaching the power transmission and reception circuit. The protection coil includes an air-core coil formed of a wiring pattern of a conductor provided on a board disposed between the power transfer coil and the power transmission and reception circuit, and at least one core coil connected in series to the air-core coil.