To bend a needle material accurately so as to obtain a target curvature in bending a short needle material in a circular-arc shape.

A stationary die 6 is composed of a freely vertically movable bolster 10 and freely rotatable movable receiving parts 11 arranged on both sides of the bolster 10. A moving die 7 is provided with a pressurizing shaft 30 corresponding to a target curvature, lowering the needle material 1 while its center part is held between the pressurizing shaft 30 and the bolster 10, and pressing the center part of the needle material against the pressurizing shaft 30, as the primary bending process. Then, both ends of the needle material 1 are positioned above the movable receiving parts 11, whose rotation allows to press both ends of the needle material 1 against the pressurizing shaft 30 as the secondary bending process. Thus, the needle material 1 is bent into a circular arc shape by bringing the material into close contact with the outer circumferential surface of the pressurizing shaft 30.