To simply fit an anchor bolt to a wall body not accessible with hands by pushing-open one end section of a tube body to form open pieces with the tapered head section of one end section of a central shaft body, pinching the wall body with the open pieces and a pinch nut, and using the protruded portion of the tube body from the pinch nut as a screw shaft section.

A tube body 3 inserted with a central shaft body 4 is inserted into the insertion hole 2 of a wall body 1, and one end section of the tube body 3 is protruded from one face 10 of the wall body 1. A washer 12 is outwardly coupled with the thread ridge 6 on the outer periphery of the other end section of the tube body 3 on the other face 11 side of the wall body 1, a pinch nut 13 is screwed, and a screw shaft, section 14 is protruded from the pinch nut 13. A thrust-open nut 15 is screwed to the thread ridge 8 on the outer periphery of the other end section of the central shaft body 4, one end section of the tube body 3 is thrust-open to form open pieces 16 by a tapered head section 7 at one end section of the central shaft body 4, the wall body 1 is pinched by the open pieces 16 and the pinch nut 13, and the protruded portion of the tube body 3 from the pinch nut 13 is used as the screw shaft section 14. A fitting member such as a handrail is screwed to the screw shaft section 14.