A substrate processing system includes a protective film forming liquid supplying unit which supplies a protective film forming liquid to one surface of a substrate, a protective film forming unit which solidifies or hardens the protective film forming liquid and forms a protective film on the one surface of the substrate, a suction unit which suctions the one surface of the substrate, a processing unit which executes predetermined processing with respect to the other surface of the substrate in a state that the one surface of the substrate is suctioned by the suction unit, and a removing liquid supplying unit which has a removing liquid discharge port that discharges a removing liquid being capable of removing the protective film and supplies the removing liquid toward the one surface of the substrate from the removing liquid discharge port.