PURPOSE: To make it possible to obtain uniform thin plates, simultaneously, by providing such an arrangement that a hard workpiece are moved upward relative to a plurality of endless blades which run in one direction at a constant speed, and therefore, the workpiece is cut into a plurality of cut pieces, at the same time.

CONSTITUTION: A plurality of endless blades 7 which are wound around a pair of flywheels 39, 61 and therefore run, are regulated by a pair of plate guides 15, 17 so that they are arranged at predetermined intervals, and their entire tension is regulated by a tension regulating motor, while their individual tensions are regulated by tension applying devices 19, 21. Further, a workpiece set on a workpiece loading and moving section 5 is moved up and down, back and force, relative to the plurality of endless blades 7 moving in one direction, and therefore, is cut into a plurality of thin pieces, at the same time. Thus, it is possible to cut a hard workpiece made of silicone, ceramic or the like, into a plurality of uniform thin plates, simultaneously, thereby it is possible to enhance the efficiency of cutting.