To solve conventional problems that construction materials for fixing reinforcing bars are not avaialbe currently and reinforcing bars protrude on a surface of concrete in many cases because it is very important to ensure a thickness of cover concrete so as to ensure dignity and strength of a building when the reinforced concrete building is constructed.

A separator for fixing forms on the inside and the outside is used to solve the problems. First, recessed channels are provided in a part having the thickness of cover concrete of the separator (round steel type, flat steel type) at positions (30 mm, 35 mm, 40 mm, 45 mm, 50 mm) to correspond to sections having different thicknesses of cover concrete and thickness of reinforcing bars, and reinforcing bars are bound and fixed by binding wires on an inner side (center of wall) using the channel as a start point to ensure the thickness of cover concrete. Furthermore, a width fixing bar and a spacer are not used to reduce an object preventing the flow of concrete and prevent the occurrence of a rock pocket when placing concrete.