To make the attachment and removal of a handrail easier during the curing of wall or floor openings by using a handrail attaching device having tightening handles, tightening screws and push plates for the main body of a plate having a hole for inserting a bar-shaped handrail member.

A handrail attaching device is provided by using a tightening handle 2, a tightening screw 3 and a push plate 4 to the main body 1 of a plate with a hole opened for inserting a bar-shaped handrail material 5. The main body 1 is attached with a handrail member 5 and butted to an end of the opening, and the tightening handle 2 at one side is turned. Then, the push plate 4 pushes a thing to be supported 6 at the end portion through a tightening screw 3, and by its reaction, the main body 1 can be fixed to the handrail member 5. In the same manner, if the tightening handle 2 of the main body 1 at the opposite side is turned, fixing can be made stronger. When curing the openings in a wall or a floor, the thing to be supported can be easily attached to both the ends of the opening and also removed when necessary.