To solve the problem that useful materials in composite waste debris are recovered with a dry selection process manually, magnetically, or the like, but the recovery effect is low or the cost is high, accordingly, 80% or more useful materials are contained in the composite waste debris to be dumped in the final disposal site.

Materials separated into composite elements by combination processes of wet devices are separated and purified into around ten kinds of elements every materials, and the useful materials are recovered as 80% or more raw materials or fuel, thus resources are ensured and landfill at the final disposal site is reduced, thereby solving the environmental problems.