PURPOSE: To allow the sepn. of a waste liquid to moisture and insoluble matter and the adequate processing of the insoluble matter and to make a contribution to environmental beautification.

CONSTITUTION: A waste liquid storage and evaporation tank 154 of a box type is disposed below an overflow pipe 70. A thin vinyl sheet member 156 is laid along the inner peripheral surface in the waste liquid storage and evaporation tank 154. A heater unit 160 is mounted on the base of the waste liquid storage and evaporation tank 154 so that the waste liquid in the waste liquid storage and evaporation tank 154 is heated. The temp. of the waste liquid, therefore, rises and the moisture evaporates eventually. Since development scum 18A generated at the time of development is included in the waste liquid, only the development scum 18A remains after the concentrating of the waste liquid on evaporation of the moisture. This development scum 18A can be easily taken out of the photosensitive storage and evaporation tank 154 by lifting the sheet member 156.