There is disclosed a bending device, in which working data of feeding pitch between bending points, bending direction angle and bending angel is prepared from design data of a work, and a dividing point is determined to share the bending process by first and second joint type robots at one place of a straight line of the work able to be held by a chuck mechanism. After trial working, the working data is corrected. During the working, the first and second joint type robots having joints rotatable around axes parallel with the axial direction of the work are moved to the bending position. The work is held by a bending die and a clamping die rotatable around the bending die of a bending mechanism attached to the tip end of each joint type robot, and bent/worked by rotating the clamping die. When moving to the next moving position each joint is rotated to change the attitude of the bending mechanism, and the bending mechanism is moved along the work while the work remains between the bending die and the clamping die. After the bending process is completed, the work is held by the beading mechanism of the second joint type robot, moved in accordance with the angle of the bending mechanism of the first joint type robot in a direction in which the bending mechanism of the first joint type robot is not interfered with, and automatically moved to the unloading position.