To provide a method for manufacturing an exhaust tube capable of achieving a more weight saving tube.

An exhaust tube which guides exhaust gas discharged by connecting the clearance between an internal combustion engine and a muffler is manufactured. By leaving a welding section to weld a flange in the end of at least one end, a thinning section 1a is formed and simultaneously, the exhaust tube is manufactured from a tube stock 1 formed so that the outside dia. of the thinning section 1a and the outside dia. of the welding section have the same size. By inserting a core bar 26 that can be enlarged in the diameter direction into the tube stock, and by swaging the core bar 26 enlarged from the outer periphery side of the tube stock 1, the thinning section 1a is formed.