Abstract: A crushing device comprises a crushing mechanism for crushing an object, the crushing mechanism performing the crushing operation by a stationary blade and a crushing rotor which is rotationally driven by a crushing motor; a conveying mechanism for pressing and conveying the object to the crushing mechanism by a conveying roller rotationally driven by a conveying motor; a pressing mechanism for pressing the conveying mechanism to the object by an arm cylinder; and a hopper for receiving the object. The drive force of the arm cylinder is controlled according to the drive load of the conveying motor, and the rotational speed of the conveying motor is controlled according to the drive load of the crushing motor.