PURPOSE: To make the improvement of cutting accuracy and reduction in cutting cost compatible by detecting the moving speed of a body and the quantity of its displacement through the movement of the tip of the body.

CONSTITUTION: A cutting device is provided with a stopper 7 for a body 1 and a digital scale 9 which measures the quantity of displacement and moving speed of the body 1 and issues a pulse signal corresponding to each of the above items. A signal synchronizing with the signal issued from the digital scale 9 is issued to a servo-motor 6 through a synchronizing circuit 18 to correct lag error occurring until the servo-motor 6 attains a fixed speed. Thus the highly accurate continuous cutting of a square lumber or a paper pipe can be inexpensively executed independently of the kind of the body 1.