Cleaning device of beverage supply system

This cleaning device for a beverage supply system (1, 1 ') is provided with: a dispensing head (50) having a fluid outlet (52) and a fluid inlet (51); an air supply path (60) connecting the air supply source (10) and the fluid inlet; a gas on-off valve (61) that opens and closes the gas supply path; a water supply path (90) connecting a water supply source (100) and the fluid inlet; a water on-off valve (91) that opens and closes the water supply path; a pressure sensor (44) that detects the pressure of the gas supply path downstream of the gas on-off valve; and a control device (80) that controls the gas on-off valve and the water on-off valve. The dispensing head is configured to be manually switched between a first state in which the fluid inlet and the fluid outlet communicate with each other via the inside of the beverage container, and a second state in which the fluid inlet and the fluid outlet directly communicate with each other. The control device detects a misoperation of a user of the beverage sup