The invention provides a wireless power transfer system and a load apparatus in the same wireless power transfer system. In wireless power transfer with applying magnetic resonance therein, for suppressing deterioration of transfer efficiency, with lessening fluctuation of the resonance frequency when a distance between coils is close to, coils are so position that a supply-side power supply coil101 and a load-side power supply coil 102 are inserted between a supply-side magnetic resonance coil 1 and a load-side magnetic resonance coil 2.