To produce a metal carrier integrated with an outer cylinder, from which an exhaust gas is not leaked, with the thermal stress easily distributed and using a laser beam and to provide a method thereof.

Metallic corrugated sheet 12 and flat sheet 11 are alternately laminated to constitute a metal carrier element 10, the flat sheet 11 leaving a length to wind the periphery of the element 10 once or twice is held by thick plates 14 forming the outer cylinder to form an outer layer 15 on the periphery of the element 10, the thick plate 14 is wound on the outer layer 15 at least by one turn, and an outermost layer 21 with the terminal end 14b fixed is provided. The element 10 is welded to the outer layer 15 wound on the periphery of the element 10 by a laser beam 17 emitted from outside the outer layer 15, and a piercing part 18 due to the laser beam 17 formed in the outer layer 15 is closed by the outermost layer 21.