PURPOSE: To produce a composite pipe made of tungsten-stainless steel which is high in bonding strength by introducing a gaseous raw material contg. tungsten halide and hydrogen into a heated pipe made of stainless steel.

CONSTITUTION: A pipe 1 made of stainless steel is arranged in a reaction vessel 11 which is held in the atmosphere of inert gas such as Ar to prevent oxidation. Electricity is directly conduced to this pipe 1 via the water-cooling terminals 2a, 2b made of copper from a DC power source 3, and the pipe 1 is heated. This temp. is measured with a photothermometer 13 from an observation window 12. The DC power source 3 is controlled via a temp. controller 14 to hold the pipe 1 at about 700°C. Then, a gaseous raw material contg. tungsten halide such as WF6 and hydrogen is introduced into the pipe 1 through an introduction pipe 6. Then, tungsten is grown in a gaseous phase on the inner surface of the pipe 1 and a deposited tungsten layer 15 is formed. Thereby, a composite pipe is obtained wherein the tungsten layer 15 is strongly bonded to the pipe 1 made of stainless steel.