PURPOSE: To prevent a cutting surface from being oxidized continuously by atmosphere and to thin the material through hot rolling by carrying out piercing rolling, removal of an oxidized layer, sealing the inside and outside surfaces of a pipe stock, drawing and removal of sealing of the pipe body.

CONSTITUTION: A tube stock having a thickness ≥6mm is made by a piercing mill having a pair of inclined rolls through hot piercing rolling from a titanium round bar as material. That tube stock is cooled to remove a hardened layer by oxidation generated on the inner and outer surfaces by cutting. In this tube stock 1, the inner surface is sealed by a carbon steel body 2 and the outer surface is sealed by a carbon steel body 3, then, both ends are welded and closed. A space partitioned by the tube stocks 2, 3 forms a complete vacuum by deairing and the cut surface of the tube stock is prevented completely from oxidation. Then, the whole assembled body is drawn such as pierced and rolled and formed into a prescribed dimension, then cooled. Then, as occasion arises, cold reduction working is performed, thereafter, carbon steel is removed by giving a nitric acid bath, for example, to obtain a titanium or titanium alloy tube.