PURPOSE: To simplify the regulating work, as well as to simplify the structure of a metal fitting to regulate the height of the space under the floor by the screwing condition of a screw.

CONSTITUTION: A female screw is engraved on the inner surface of a cylindrical driving nut 1 with flange which has a flange 11 and plural projecting lines 13, a regulating bolt 2 which has a male screw at the upper part is screwed to the female screw, while a truncated conical rubber board 3 is installed to the lower side of the regulating bolt 2. When the height of the floor is regulated, a driver is inserted from the upper side of the driving nut 1 hit in the particle board of an underfloor member, so as to engage to the head of the regulation bolt 2, and the height of the floor is regulated by regulating the screwing condition, by the operation of the driver.