In a method for manufacturing a treatment tool according to the invention, the treatment tool includes a function body, a tube portion, and an operation unit. The function body has at least one elastic wire formed of a wire material made of a super-elastic material and having a predetermined shape, and a fixing portion having an insertion hole into which the elastic wire can be inserted to house at least a proximal end portion of the elastic wire in the insertion hole so as to be fixed to the fixing portion. The tube portion is configured to house the function body. The operation unit inserts and removes the function body into and from the tube portion. The method includes an insertion step of inserting the proximal end portion of the elastic wire (6211 to 6214) into the insertion hole of the fixing portion (622), a formation step of forming, at the proximal end portion of the elastic wire (6211 to 6214), an engagement portion for engaging with the insertion hole of the fixing portion (622), and a fixing step of fixing the proximal end portion of the elastic wire (6211 to 6214) to the fixing portion (622).
