To modify a conventional insert since it is troublesome that a number of the inserts are mounted and demounted though the conventional insert is integrally formed by driving or screwing.

This insert comprises an anchor 1 in the shape of a cylinder with a bottom, and a jig for form insertion. Into the hollow cylinder body of the insert jig, a bush rod 10 is rapidly inserted and fixed to the bottom of the anchor 1 in the shape of a cylinder with a bottom by a bush rod 10 provided at a tip with a magnet 9 or a pressure-sensitive adhesive double coated tape 3, and an outer return spring 11.