CONTACTLESS POWER SUPPLY DEVICE CAPABLE OF DETECTING METALLIC FOREIGN OBJECTS AND METALLIC FOREIGN OBJECT DETECTION METHOD THEREFOR

A non-contact power feeding device feeds electric power in a non-contact manner from a transmission coil 31 installed on ground to a reception coil 32 of a mobile object stopping at a feeding position. The device includes, on the ground, an inverter 20 that outputs a high-frequency alternate current to the transmission coil 31, and a metal detecting-determining unit 40 that detects a metallic foreign object on the transmission coil. The metal detecting-determining unit 40 monitors the phase of a voltage and a current output from the inverter 20 to the transmission coil 31 and detects a metallic foreign object having entered during power feeding, based on a variation in the phase. The non-contact power feeding device can detect metallic foreign objects according to only measured data from the ground while the mobile object stops at the feeding position and can be simplified in structure.