PURPOSE: To enhance the working efficiency of sawing and the life of a saw blade to aim at enhancing the quality of finished surfaces, by providing a means for inputting as data the pitch of a bandsaw blade and the material property of a workpiece to compute an optimum peripheral speed and for controlling the rotational speed and a means for controlling the peripheral speed irrespective of both values.

CONSTITUTION: In order to set aluminum as the material of a workpiece and the pitch of a bandsaw to 18, a material property instruction switch 7 is pushed twice times while a pitch instruction switch 8 is pushed one time, and therefore, a computer 12 adds date in a memory by two and one, respectively, to recognize the material of the workpiece and the pitch and sets a peripheral speed of 75m/min to a display unit 13. Further, the computer changes date fed to a rotational speed control circuit 14. When a switch 6 is turned on, the circuit 14 continues to energize a TRIAC15 to set the peripheral speed to 75m/min, and since the computer 12 recognizes that a motor 1 rotates, through a detector 16, data in the memory and the rotational speed will not vary even if switches 7W11 are operated. When a change-over switch 9 is turned into to disable the switch 8, the peripheral speed may be set optionally by means of a switch 10.