To provide a method for manufacturing a pipe whose wall thickness is substantially uniform over the entire length, and which has projecting parts on a side surface.

In the method for manufacturing the thin-walled pipe having the projecting parts on the side surface by forming the projecting parts 2 and 2 at predetermined positions by performing the mechanical press of a thin-walled metal plate in a flat state, the thin-walled metal plate is formed in a cylinder, and end faces 3 and 4 are welded 5 to form a pipe. Alternatively, in this method, projecting parts are formed at predetermined positions of the thin-walled metal plate in a flat state by performing the mechanical press, the metal plate is joined with other metal plates, and cut to the dimension of the cylinder, and end faces of the metal plate and the other metal plate are welded to form a pipe having projecting parts on the side surface. The pipe may be further subjected to the hydraulic press.