PURPOSE: To control the cutting length by measuring (counting down) signals.

CONSTITUTION: A specified pulse is transmitted from a transmitter 1 according to the movement of a material to be cut the number of pulses (Po) for each unit length of movement of the material to be cut is calculated by a calculator 18, and the number of pulses (Px) transmitted until instruction of cutting is given is calculated by the following expression in which the number of pulses (Po) is used. Px=(L1+L2)Po Where L1: Distance between material detector on upstream from cutter and cutter. L2: Target cutting length of material to be cut. When the number of pulses Px is counted and reduced to zero, a cutting instruction is given to carry out the cutting, actual cutting time is judged by increase in current of a cutter motor 26 in cutting, and the number of pulses (Pe) transmitted during the period from the cutting instruction to actual cutting is measured. On the next time, the number of pulses of Px-Pe is counted down using the Pe and, when it becomes zero, the next cutting instruction is given to carry out the cutting.