To solve the problem that a conventional anchoring equipment lowers the extraction stop force when the holding means of a seat member is worn out and reaches to the tip side by the wearing friction in case the engagement is repeating, although a gutter case part permits the moving passage by bending with the elasticity when the engaging means prepared in the inner circumference side of the seat member rides over the top part of a serrated step part, which is because the holding means of the seat member is worn out by the wearing friction when repeating the engagement.

In a conventional anchor equipment, the serrated step parts in the gutter case part are prepared more than one in the longitudinal direction of the case part repeatedly and the step parts in the back end side of a cylindrical case part is formed smaller than the step parts in the front end side, which constitutes so that the engagement with the holding means of the seat member decreases in the back end side.