Provided is a power transmitting device, a power feeding system, and a power feeding method in which power loss is cut by increasing power use efficiency and power can be supplied to a power feeding user (a power receiving device) with high power transmission efficiency. Depending on a power feeding state (e.g., resonant frequency of a power transmitting resonance coil is not the same as that of a power receiving resonance coil, or the influence of their positional relation), power transmitted from a power source portion of the power transmitting device is reflected to the power transmitting coil side by the power transmitting resonance coil. Further, a power recovering function (circulation function) for power reflected to the power transmitting device is provided to recover the power reflected to the power transmitting coil side and to reuse it for power transmission.