There is provided a through-hole manufacturing method for a cylindrical body wall that enables the operation of forming a through-hole without leaving a machining burr on the wall of a cylindrical member to be easily and reliably carried out without depending on experts. A through-hole manufacturing method for a cylindrical body wall in which a machining burr is not formed on inner walls of through holes formed by a tool piercing the wall of a cylindrical body, the method including a hole forming step of forming one pair or a plurality of pairs of the through-holes in the cylindrical body wall by the tool piercing the cylindrical body from the outside orthogonally or substantially orthogonally to a cylindrical body axis of the cylindrical body; and a welding step of sealing the through-hole formed by the tool piercing the cylindrical body from the outer wall to the inner wall by welding using a welding jig made of a material having better heat conductivity than the cylindrical body, wherein the through-hole formed by the tool piercing the cylindrical body from the inner wall to the outer wall is left as a nozzle hole.