PURPOSE: To enhance the workability of carrying-out of waste floor materials and to reduce the cost of transporting these materials to a throwing field by finely chipping the waste floor materials by means of a finely chipping section which acts shearing and cleaving or both effects thereof synergistically on the waste floor materials.

CONSTITUTION: The finely chipping section 1 finely chips the waste floor materials W by the shearing effect and cleaving effect or the synergistic effect of both thereof. Namely, this section has a pair of rollers 8 consisting of cylindrical or columnar roller bodies 9 and many blade bodies 19 projected from these roller bodies 9. Both rollers 8 partially overlap the rotating regions of the respective blade bodies 10 on each other and are so disposed that the blade bodies 10 of the two rollers 8 intermesh each other. The two rollers are driven by a driving device 11 in such a manner that the rollers are rotated reverse from each other. As a result, the waste floor materials are made into fine pieces of below a specified size.