To avoid irregular power feeding and power generation of a metal material to realize save power consumption using only the power feeding circuit to supply non-contact power even when a metal material other than the regular power receiving coil is arranged in the opposing positions of power transmitting coil.

A substance coupled by magnetic inductance effect with an LC parallel resonance circuit 14 in the power transmitting side is detected a resonance frequency generated by a frequency follow-up circuit 18 of a mutual inductance detector 17. As a result, when a load detecting circuit 19 has detected the maximum power transmission amount, a regular power receiving side LC parallel resonance circuit 21 is determined to be arranged and the oscillation circuit 16 continuously oscillates the transmission frequency for transmitting the power. On the other hand, the oscillating circuit 16 oscillates intermittently in other cases and also oscillates the frequency other than the transmission frequency and thereby power of the resonance frequency for reducing the power transmission amount can be saved by a power transmitting side voltage control circuit 12 or a current limiting resistor 13.