To provide a most theoretical fixture that allows a display board and a display unit, such as a temporary signboard for construction, to be fixed more firmly and rationally, and also achieves self-holding of a fastening portion.

A normal screw and a reverse screw are provided in one shaft while divided with respect to the shaft center, and inside screw parts are inserted into them respectively, to open/close the inside screw parts. With such a structure, the fixture holds the structure of self-holding to secure firm fastening.