PURPOSE: To prevent a material to be worked from breaking and to obtain a tubular body with a small diam. and the thin wall thickness, by inserting a separted mandrel into the other end of a tubular material to be worked to which a mandrel is inserted, and drawing the material through a die while adding a backward tension to it.

CONSTITUTION: Mandrel 18 is inserted into a tubular material to be worked 3 and a separate mandrel 19 is also inserted into the other end part of the material 3. Next, the other end part 9 and the mandrel 19 are clamped together by a chuck 10, and the material 3 is pulled to the direction of the arrow 15 by a weight 14, and together, and one end part 4 of the material 3 is passed through a die 2 to be clamped by a chuck 5. Then, when the chuck 5 is moved to the direction of the arrow 6, the material 3 is passed through the die 3 to be processed successively while being given the backward tension to the direction of the arrow 15.