To provide a closed recovery system of an information recording medium which can be applied to all waste recording media irrespective of the shapes of tapes, disks and the like, and can recycle the treated medium, has a high raw material recovery percentage, and can be materialized at low costs by simple equipment.

A waste recording medium 1 is separated in a medium into a substrate and a solution containing a recording layer by an agitating/ separating cleaning separation layer 4, and the substrate is recovered, the solution is separated into supernatant 20 and a deposit 19 containing a metal substance as a main component by a precipitation separation tank 8, the metal substance is recovered, and the supernatant 20 is reused as the medium in the tank 8.