To obtain a device for treating the dehydrated cake of cement sludge, waste concrete, wood, charcoal, brick, coal, coke, tile, ALC building material or the like.

Two rotors 2 and 3 with at least the one connected to a power source are combined at the upper part of a case, (a) relatively narrow partition teeth 8 are arranged to the rotors alternately in front and in rear with many small cut teeth, (b) laterally long teeth are arranged on both sides of the partition tooth parallel, a chute space is formed to house a small piece after being demarcated in the valley with the four sides restricted, and the demarcating teeth 9 and 10 with their bottom face inclined are furnished, and (c) uncutable discharge teeth 11 are arranged adjacent to the inclined bottom face of the demarcating teeth. Further, a feed port is formed between rotors.