A process for treating a photographic processing waste solution which comprises: placing a polymer precipitate in a lower portion of a tank having a U-shaped treating space which comprises (i) a first partition, (ii) a second partition and (iii) an interconnecting partition for interconnecting the first partition and the second partition in the lower portion of a tank; introducing into the first partition a photographic processing waste solution containing a processing solution having fixing ability which has processed a silver halide photographic material; treating the photographic processing waste solution in the U-shaped treating space in the presence of a polymer having S atom which can coordinate with a metal; and removing the metal in said photographic processing waste solution.