To provide a bending system and a bending method in which a measuring device for measuring a one-sided elongation value of a work clamped by a robot is small-sized and its constitution is simple and, the efficiency of measurement is improved by shortening measuring time, the range of the measurement is expanded by taking a work the bending angle of which is not only 90° but also acute or obtuse as the object of measurement, the work is positioned by using the measuring device for measuring the one-sided elongation value of the work and the bending work is performed with the robot without interfering with a machine main body.

This apparatus has a gripper 14 of a robot 13 for clamping a work W and a measuring device 1 for measuring the one-sided elongation value α of the work W which is attached to the gripper 14.