A wireless power supply system includes a plurality of primary coils and a movable secondary coil. The primary coils excited by the supply of high-frequency current are configured so as to generate an alternating magnetic field by which secondary power is generated in the secondary coil. The resonance characteristics of a resonator including excited primary and secondary coils vary with the movement of the secondary coil within a varying range. The power supply frequency (fn) of the high-frequency current is set to the frequency (fp) corresponding to the intersecting point (P) between a first resonance characteristic line and a second resonance characteristic line, which correspond to the respective two ends of the varying range of the resonance characteristics and are farthest apart from each other.