A power feed system, comprising: a power feed device; and a power receiving device, wherein the power receiving device includes a power receiving section (32, 33) configured to receive power wirelessly from the power feed device with use of a power receiving coil, and a first communication section configured to transmit coil information to the power feed device, the coil information indicating whether or not a coil of the power receiving device is provided near the power receiving coil and including the number of resonant points in a third resonant circuit configured by a coil when provided near the power receiving coil, and the power feed device includes a power feed section configured to supply power wirelessly to the power receiving device with use of a power feed coil, a second communication section configured to receive the coil information, and a controller configured to perform, on a basis of the coil information, a first determination as to whether or not to supply power to the power receiving device, and configured to control an operation of the power feed section on a basis of a result of the first determination, and, a first measuring section configured to measure a first frequency characteristic of a first parameter in a first frequency range on a basis of a signal at the power feed coil and to measure the number of resonant points in the first frequency range on a basis of the first frequency characteristic, and wherein the controller performs the first determination on a basis of the first frequency characteristic in addition to the coil information, wherein the first determination is performed on a basis of the number of resonant points in the first frequency range by comparing the number of resonant points in the first frequency range with the number of resonant points included in the coil information. a power feed device; and a power receiving device, wherein the power receiving device includes a power receiving section (32, 33) configured to receive power wirelessly from the power feed device with use of a power receiving coil, and a first communication section configured to transmit coil information to the power feed device, the coil information indicating whether or not a coil of the power receiving device is provided near the power receiving coil and including the number of resonant points in a third resonant circuit configured by a coil when provided near the power receiving coil, and the power feed device includes a power feed section configured to supply power wirelessly to the power receiving device with use of a power feed coil, a second communication section configured to receive the coil information, and a controller configured to perform, on a basis of the coil information, a first determination as to whether or not to supply power to the power receiving device, and configured to control an operation of the power feed section on a basis of a result of the first determination, and, a first measuring section configured to measure a first frequency characteristic of a first parameter in a first frequency range on a basis of a signal at the power feed coil and to measure the number of resonant points in the first frequency range on a basis of the first frequency characteristic, and wherein the controller performs the first determination on a basis of the first frequency characteristic in addition to the coil information, wherein the first determination is performed on a basis of the number of resonant points in the first frequency range by comparing the number of resonant points in the first frequency range with the number of resonant points included in the coil information.