The wire insertion tool by the present invention includes: a first division block having a first wire insertion guide ditch forming plane where a first wire insertion guide ditch has been formed; a second division block having a second wire insertion guide ditch forming plane where a second wire insertion guide ditch has been formed; and a division block positioning guide. When the first division block and the second division block form a coupling unit by fitting the first wire insertion guide ditch forming plane and the second wire insertion guide ditch forming plane, the first wire insertion guide ditch and the second wire insertion guide ditch form a wire insertion guide hole. The division block positioning guide guides one of these blocks linearly to the other such that these planes approach to each other or separate from each other.
