PURPOSE: To cut off the unacceptable portion of a rolled strip at its end part by at the optimum cutting point while the shape of the strip end part is grasped accurately.

CONSTITUTION: The shape of the end part of a rolled strip is grasped by an image processing means 13 on the basis of image signals for the strip end part generated by a photographing device 11. The shape image signals are fed to a neural network constituting part of an end part shape acknowledging means 14, to make shape evaluation of the end part and the evaluation on the time basis where changes with elapse of the time are taken into account, and the results are forwarded to a cutting point deciding means 15. The means 15 decides the cutting point by applying the results from evaluations to the IF- THEN rule, and thereupon the bad portion at the end part is cut off.