A contactless power supply system comprising: a device; and a power supply apparatus that supplies power contactlessly to the device, wherein the power supply apparatus includes: a plurality of primary coils provided in a planar or linear manner; a plurality of power supply modules respectively corresponding to the plurality of primary coils, each of the power supply modules configured to receive an excitation request signal for requesting excitation of the primary coil and excite the primary coil based on the excitation request signal; and a system control section configured to integratedly control the plurality of power supply modules, the device includes: a secondary coil; and a transmitter circuit that sends the excitation request signal to the power supply apparatus, when the device is mounted on the power supply apparatus, the contactless power supply system excites primary coils corresponding to one or more power supply modules, generates secondary power in the secondary coil of the device by electromagnetic induction, and supplies the secondary power to a load of the device, and when the excitation request signal from the device mounted on the power supply apparatus is received at the one or more power supply modules, the system control section sends an enable signal for exciting the primary coils to the one or more power supply modules that received the excitation request signal, wherein each of the plurality of power supply modules includes: a high frequency inverter circuit that excites the primary coil; a receiver circuit that receives the excitation request signal from the device and identifies the excitation request signal; and an excitation control circuit that generates a drive control signal for driving the high frequency inverter circuit when the receiver circuit receives the excitation request signal, wherein each of the plurality of high frequency inverter circuits includes: an oscillator circuit that excites the primary coil; characterised in that each of the plurality of high frequency inverter circuits includes a synchronizing signal generator circuit that drives the oscillator circuit in response to the drive control signal from the excitation control circuit, wherein the plurality of power supply modules excites the plurality of primary coils at the same phase upon driving the plurality of primary coils to be excited. a device; and a power supply apparatus that supplies power contactlessly to the device, a plurality of primary coils provided in a planar or linear manner; a plurality of power supply modules respectively corresponding to the plurality of primary coils, each of the power supply modules configured to receive an excitation request signal for requesting excitation of the primary coil and excite the primary coil based on the excitation request signal; and a system control section configured to integratedly control the plurality of power supply modules, a secondary coil; and a transmitter circuit that sends the excitation request signal to the power supply apparatus, when the device is mounted on the power supply apparatus, the contactless power supply system excites primary coils corresponding to one or more power supply modules, generates secondary power in the secondary coil of the device by electromagnetic induction, and supplies the secondary power to a load of the device, and when the excitation request signal from the device mounted on the power supply apparatus is received at the one or more power supply modules, the system control section sends an enable signal for exciting the primary coils to the one or more power supply modules that received the excitation request signal, a high frequency inverter circuit that excites the primary coil; a receiver circuit that receives the excitation request signal from the device and identifies the excitation request signal; and an excitation control circuit that generates a drive control signal for driving the high frequency inverter circuit when the receiver circuit receives the excitation request signal, an oscillator circuit that excites the primary coil;