PURPOSE: To prevent the rotation of a female screw member by integrally protrudingly molding a fixed piece part on a body subjected to mounting, providing a through-hole near it or in a part including it, inserting the embedded female screw member thereto, nipping the body subjected to mounting between an intermediate swollen part and a flange, and covering the fixed piece part with the swollen part.

CONSTITUTION: A fixed piece part 14 having a substantially square section is provided on the inside 10a of a body 10 subjected to mounting in parallel to the longitudinal direction of the body 10 so as to be integrally continued thereto, and a through-hole 10c capable of inserting a cylindrical embedded female screw member 50 is provided on the longitudinal central line thereof. The female screw member 50 has a flange on the upper part. The female screw member 50 is inserted to the through-hole 10c, and the male screw part of an exclusive tool is screwed to the female screw part 50b of the female screw member 50. When the male screw part is pulled up, the flange lower part of the female screw member 50 is horizontally swollen by compression to form a swollen part, which covers the fixed piece part 14 to form a rotation preventing part 15. Thus, the rotation of the female screw member 50 can be prevented.