PURPOSE: To secure a coming-off stopping effect which is fixed and accurate at all times, by cutting off a bolt main body at a fixed position, protruding it in the outer direction.

CONSTITUTION: A coming-off preventive bolt is assigned from the top of a light-weight concrete panel K, and the head portion 11 of the bolt body 1 is hit with a hammer or the like. As the bolt body 1 and a sleeve body 2 are coupled together at the lower portions, they are run into the light-weight concrete panel K portion integrally, and then at a flange portion 21, the sleeve body 2 is stopped. When hitting is continued on, shearing force works at the place of the cut-in portion 14 of the bolt body 1, and when a certain limit is reached, breaking is carried out at the cut-in 14, and the coming-off stopping portion of the bolt body 1 is moved along a cut-in surface (a) that has become a slope, and starts to protrude outward through the window portion 22 of the sleeve body 2 by seeking an outlet. As for the head portion 11 of the bolt body 1, the advance of the bolt body 1 is stopped at the place of the flange portion 21 of the sleeve body 2, but the coming-off stopping portion 15 protrudes completely by a fixed distance to the side surface from the sleeve, and bites into the light-weight concrete panel K, and the whole of the coming-off preventive bolt is surely fixed.