To reduce working cost by making a transmission device, which is successively arranged with a inclining device, a self running moving device in bending a member to be worked so as to reduce handing time and cost.

By operating a chuck arm 25 for opening/closing, the outer periphery of a work is held by a chuck claw 23. By running a vertical self running device 30b, a bending point of the member to be worked is positioned at the right side of center of a bending die 17. By operating a bending device slide actuator 13, a bending device 10 is positioned. The outer periphery of member to be worked is fitted in the groove part of bending die 17. A mandrel 41 is inserted in the hollow part of member to be worked, further, moved to the position of bending point. A clamp die 16 is abutted on the member to be worked so as to be protruded. By operating a pressure actuator 19, a pressure die 18 is abutted on the member to be worked and pressed on the bending die 17. By following the pressure die to turning of the bending die 17 and clamp die, the member to be worked is bent.