A fluid supply system includes: a support body having: a base plate; a side plate provided on one side of the base plate in the longitudinal direction so as to be orthogonal to the base plate; and a top plate provided on one end of the base plate in the height direction so as to be orthogonal to the base plate and the side plate; a process-gas supply unit provided on an outer surface of the top plate; a liquid supply unit provided on an inner surface of the side plate so as to communicate with the process-gas supply unit via a communication-flow-channel forming block; and a purge-gas supply unit provided on an inner surface of base plate so as to communicate with the process-gas supply unit via a communication pipe.