There is provided a kind of seal wire has structure novel, production efficiency can be improved by it and to effectivelying prevent from forming big irregular periphery core wire. Additionally, it is provided a kind of seal wire has structure novel, flexural rigidity can be more carefully set, so as to its distal portions. In seal wire 10, so that coil 14 is mounted on about distal portions core wire 12, the proximal part 14 of coil is integrally connected to the coil 14. of core wire 12Formation during in addition, in seal wire 10, therefore, coil 14 is mounted on around end section core wire 12, and section line 24 constitutes the coil 14 of the length direction variation of coil 14.
