To perform crush and recovery at a low cost by crushing waste resin moldings consisting of tough resin material incapable of being crushed at ordinary temperature or thermally reducible resin material by a relatively simple and easy method.

Waste resin moldings are crushed into a plurality of small pieces to be treated 12, and thereafter these small pieces to be treated 12 are heated, preferably, they are heated at the thermally reducible temperature or higher of these small pieces to be treated 12 so as to render these small pieces to be treated 12 reducible. These heated individual small pieces to be treated 12 are imparted with compression impact forces on the basis of microvibration in order to be crushed, thereby forming thin extended flat small pieces to be treated 13. When impact shearing forces are applied to these flat small pieces 13, since these flat small pieces 13 are thin, they are cut and crushed readily without being affected by heat of the impact sharing forces, thus forming graded resin material 14 to be recovered.