PURPOSE: To enable the presence of a work piece to be positively detected automatically by making the movable vice of a feed vice come close to a stationary vice, and thereby comparing the value of the detected distance from the stationary vice with the width of the work piece stored in a memory.

CONSTITUTION: The distance L1 from the tip end of a stationary vice 33 to the tip end of a movable vice 35 is set in advance, the movable vice 35 is moved to the stationary vice 33 side by a hydraulic cylinder 37 via a piston rod 49, the amount of movement is counted by a counter 71 while the revolution of a contact roller 63 is being detected by an encoder 67, the amount of the movement L2 of the movable vice 35 is operated by an operating device 73 so that the actual distance L from the tip end of the stationary vice 33 is thereby operated. The distance L is inputted into a comperator 75 so as to be compared with the width L0 of the work piece W stored in a memory 77. When L is equal to L0, it is judged that the work piece is present, the work piece W is thereby clamped so as to be forwarded to a cutting section so that it is cut off to be of a desired length. When L is smaller than L0, it is judged that no work piece is present, a signal is transferred to a NC device 79 so that commands for a process disposing of remaining members left after cutting and for the supply of a following work piece W are directed.