PURPOSE: To keep a solvent in a main tank at uniform purity by supplying a replenishing solvent to the main tank according to the frequency of use of an applying roller, and simultaneously, discharging the solvent in the main tank to a waste solution tank.

CONSTITUTION: Since sensitized material 16 is carried in successively at a specified interval, water 70 repeats rising up by an applying roller 52 and returning to a main tank 72. A sensor 88 sends a signal to the arithmetic circuit of a microcomputer 86 at every time the photosensitive material 16 is carried. When the value goes to a specified value, a solenoid valve 80 opens and water 70 in the main tank 72 goes to a waste solution tank 84. A pump 81 is operated a little later, and replenishing water is supplied from a replenishing tank 82 to the main tank 72. The applying roller 52 is rotated, and gelatin, etc., separated from the sensitized material 16 stuck to the applying roller is washed off. The solenoid valve 80 is opened again and replenishing water is supplied. Thus, the contamination of the solvent responding to the application of solvent by the applying roller can be prevented.