PURPOSE: To form a bent part by bending a bar into a desired geometrical shape by mechanisms that both outlet parts of bending device and feeding device cooperate each other, and they are positioned each other by the rotation of the satellite part around a center main body.

CONSTITUTION: When putting the bar 21 between the feeding device 12 and a chucking device 13, the bar 21 is clamped by the feeding device 12, and is sent forward in the tangent direction to an idle roller 30 for abutting. When a bent part 39 is formed and a rotation arm 28 is rotated in the direction of an arrow 41, a bending roller 29 is returned on the right side of the bar 21. When the bar 21 is positioned in a prescribed position, the chucking device 13 is operated, the bending device 11 is rotated in the direction of an arrow 41, and the bent part 39 is formed.