PURPOSE: To prevent the generation of fur by using the water brought into contact with a bacterium-proofing agent, further separating the water and suspended matter, treating the water with a reverse osmosis membrane and reusing this water.

CONSTITUTION: A photosensitive material S introduced into a body case is successively transported in a developing tank 2, a fixing tank 3 and a washing tank 4 by respective rollers 51 to 54. The photosensitive material is immersed into respective processing liquids during this time and is subjected to processing of developing, fixing and washing. Further, a reverse osmosis treating device 102 and a cleaning means are respectively provided. The cleaning means is provided with a bacterium-proofing and cleaning device 93 for subjecting the water to be returned to the washing tank 4 to a bacterium-proofing treatment and a separating means for separating the suspended matter of the liquid. Namely, the water in the washing tank 4 is introduced through a pipeline 9a to the reverse osmosis treating device 102 and is subjected to the reverse osmosis treatment. The reverse osmosis membrane is used in this treatment. The washing water is treated by the separating means for separating the suspended matter before being introduced to the reverse osmosis treating device 102. A filter 91 is provided as the separating means.