To minimize excessively high output or increases in magnetic-flux leakage by controlling power feeding on the power-feeding side if an unforeseen situation occurs. This power-feeding device (100) feeds power to an external power-receiving device (150) in a contactless manner. A power-feeding coil (103) uses electromagnetic power to feed electrical power to a power-receiving coil (154) in the power-receiving device (150). While power is being fed from said power-feeding coil (103), a power-feeding-side control unit (107) determines the amount of displacement of the power-feeding coil (103) and, on the basis of the determined displacement amount, controls the amount of electrical power being fed.