The automatic cleaning system according to the present invention comprises a radio wave generating device 70, a radio wave receiver antenna 61 for receiving a radio wave transmitted from the radio wave generating device 70, and a radio wave-strength measuring circuit 62 for measuring strength of the radio wave received by the radio wave receiver antenna 61. When radio wave-strength measured by the radio wave-strength measuring circuit 62 exceeds a predetermined threshold level, the number of revolutions of drive wheel motors 42R, 42L, a main brush motor 52, a side brush motor 58 and a suction motor 55 which are provided at a body BD of the self-propelled cleaner 10 are reduced, and loudness of a speaker 29b is reduced.