To improve the stress corrosion crack resistance in fuel containing Cl ion by coating the surface layer of a stainless steel bellows with a film consisting mainly of Cr.

An SUS304 tube stock is formed as the bellows shape, and to both ends of the bellows, SUS304-made flanges are welded. Successively, pickling is executed with hydrofluoric acid and nitric acid. Thereafter, the heat treatment of this bellows is executed by holding at about 400°C for about 60 min under vacuum atmosphere in a vacuum furnace to form the projective film consisting mainly of Cr on the bellows surface. The vacuum atmosphere is made to be in the range of 1×10-4-1 Torr. In the case of exceeding 1 Torr vacuum degree, the oxide scale (oxide film consisting mainly of Fe) is developed and it cannot be obtd. to sufficiently improve the corrosion resistance. Further, in the case of being <1×10-4 Torr, since dechromium phenomenon near the surface is developed, as the same way, the improvement of the corrosion resistance is not sufficiently obtd.