A non-contact power supply transmitter system 100 transmitting an electric power from a transmitting device (TX) 200 to a receiving device (RX) 300 with a non-contact power supply transmitter method, the TX 200 including: a transmitting coil 202; a driver 204 causing the transmitting coil 202 to generate a power signal of the electromagnetic field; and an FSK modulation unit 240 transmitting an FSK signal Sf through the transmitting coil 202, the RX 300 including: a receiving coil 302; an FSK demodulation unit 330 demodulating the FSK signal Sf received through the receiving coil 302; and a controller 312 inputting the FSK signal demodulated by the FSK demodulation unit 330, the FSK demodulation unit 330 is composed of an analog circuit. The non-contact power supply transmitter system, the receiving device, and the analog circuit can realize a low power, space-saving FSK communication.