To easily and economically manufacture a metallic tube of multiple- layered structure and high quality by superposing a strip dissimilar metallic thin plate having a lateral width approximately equal to a metallic plate on one or both surfaces of the base material metallic plate to be supplied to a welding position, and welding the butted edge parts with the butted edge parts of the base material metallic plates.

A dissimilar metallic thin plate 21 drawn out from a coil 20 is pressed to an upper surface of a base material metallic plate 11 by a roller 22, and temporarily fixed by a seam welding machine 23. A double layered metallic plate 11' formed by superposing the dissimilar metallic thin plate 21 on the upper surface of the base material metallic plate 11 is spirally formed in a state that the dissimilar metallic thin plate 21 is faced inside, and the butted edges are welded to one another to form a metallic pipe of double layered structure where an inner surface of the base material metal is coated with the dissimilar metal. Whereby the metallic pipe of double layered structure having the inner surface, the outer surface or both of inner and outer surfaces of the base material metallic plate coated with the dissimilar metal, can be easily and economically manufactured.