A power-transmission-side control circuit causes a power transmission device to perform temporary power transmission when a switch provided in a power-transmission-side instrument has been turned ON, and performs ID authentication based on ID authentication information. The power-transmission-side control circuit detects the presence or absence of a foreign object during normal power transmission by monitoring a change in induced voltage in a primary coil, causes the power transmission device to stop temporary power transmission when the ID authentication information from the power reception device has not been received within a given period of time, causes the power transmission device to stop temporary power transmission when the ID authentication has failed, and causes the power transmission device to stop normal power transmission when removal, a metal foreign object, a takeover state, or a full-charge state has been detected after normal power transmission has started.