PURPOSE: To bend the working stock by a certain angle and to perform the bending into required shape by using one pair of die materials capable of controlling mutual interval and having tapering end part on the outlet side, feeding out the worked member intermittently from the outlet to move a pressing tool a certain width.

CONSTITUTION: When the member 1 to be worked is the plate stock 1', the member 1 to be worked is fed out from the outlet 14 of the die materials 10, 10 by rotating feeding rollers 13 in a prescribed angle. Then, the mutual interval (a) between the die stocks 10 is controlled to comform with the thickness (t) of the worked member 1. More, the feeding out is stopped when the prescribed positions (a) of the worked member 1 is opposed to the end part 11. Successively, the press tool 12 is moved rightward, the member 1 to be worked is pressed to the end part 11 of the outlet side to bend the position (a) by a certain angle. Subsequently, the press tool 12 is retreated, the feed rollers 13 are rotated by a prescribed angle to oppose a position (b) of the worked member 1 against the end part of the outlet side and to stop the feeding. Then, the press tool 12 is moved rightward again and the operations to bend the worked member 1 by a certain angle are repeated to perform bending work into curved shape. Further, the member 1 to be worked of the pipe stock or the like are enabled bending into required shapes.