A process for treating a photographic waste liquid containing a used processing liquid resulting from a processing step having a bleaching ability or a fixing ability in the processing of a silver halide photographic material which process comprises adding a polymer-complex-forming agent to the waste liquid in an amount in the range of from 0.5 to 4 equivalents to a metal contained in the waste liquid to thereby form a polymer-metal complex and then filtering off the polymer-metal complex with a mono-membrane filter having a pore size of 0.05 to 10 .mu.m to thereby remove the metal. A device for use in practicing the process is also disclosed.