A control device for a noncontact power supply device includes a power transmission coil for outputting an alternating magnetic flux upon receiving alternating electric power, and a power transmission control unit for controlling alternating electric power to be supplied to the power transmission coil. The power transmission control unit includes a first mode and a second mode. The first mode controls the alternating electric power to be supplied to the power transmission coil in order to transmit electric power, to be supplied to a load of a power reception device, to a power reception coil, and the second mode controls the alternating electric power for supplying electric power less than the electric power transmitted by the first mode to the power transmission coil. After being activated, the power transmission control unit selects initially the first mode.
