face of the gate type frame 84 a bending jig 86 is mounted on a top face of the front end portion of the arm 83 and a bending block 87 is provided on a top face of the bending jig 86 although not shown the bending jig 86 is slidable vertically due to the same structure as the first embodiment a hydraulic cylinder driving device 88 is mounted on each of both side faces of the arm 83 both end portions of a timing chain 89 are coupled to the pistons 88 a of the hydraulic cylinder 88 the timing chain 89 is wound such that it engages a sprocket not shown protruded from an outer periphery of the bending jig 86 reference numeral 90 in the same figure denotes material feeding mechanism which grips a rear end portion of the material w and feeds it in the axial direction and rotates it next the operation of the bending apparatus of the second embodiment will be described a rear end portion of the material w is gripped by the material feeding mechanism 90 and a predetermined switch of the control panel not shown is turned on consequently the slide frame 82 is moved so that an interval between the supporting.