To efficiently carry out a crushing operation in the optimum condition at all times by variably controlling the rotation of a helically rotational crushing blade for crushing a material to be crushed and a charging helical roll for charging the material in a prescribed falling amount mutually independently.

In a hopper-shaped crusher body 1 in which a material to be broken is charged, a helically rotational crushing blade 2 is disposed at its lower end. A charging helical roll 3 is disposed above and in nearly parallel to the helically rotational crushing blade 2. A rotational driving mechanism 4 supplies hydraulic oil discharged from a hydraulic pump 5 to two proportional electromagnetic direction and flow rate controlling valves 7 and 8, by which the rotational directions and rotational speeds of both the helically rotational crushing blade 2 and charging helical roll 3 are controlled through hydraulic motor 9 and 10, and are adjusted by using a speed difference variable controller 6. Thereby, the efficient crushing operation can be carried out in he optimum condition at all times.