Abstract: A preferred shredder dust treatment process which includes: (1) a step of executing a first crushing; (2) a step of separating and recovering metals from the first crushed product; (3) a step of a second crushing; (4) a step of separating and recovering metals from the second crushed product; (5) a step of executing a third crushing; (6) a step of collecting and recovering dust and the like by fluidizing the third crushed product to separate therefrom a fluffy dust and pneumatically transporting the separated fluffy dust to a dust collector; and (7) a step of separating and recovering non-ferrous metals, non-metals, and the like, from the third crushed product. Preferably, the shredder dust is crushed by crushers having square blades.