PURPOSE: To firmly attach a hanging metal fittings for hanging a ceiling or equipment piping to the lower, face of a floor slab.

CONSTITUTION: A hanging metal fitting body 12 has a nut 13 on its bottom and a protrusive engaging part 12g on its left end. The engaging part 12g engages a groove 1c on the oblique web face 1b of a deck plate 1. An engaging member 14 with a claw 14b is attached to the hanging metal fitting body 12 so as to be movable right and left. A saw-tooth 15b to engage with the claw 14b is fixed on the side of the hanging metal fitting body 12. A crooked plate spring 17 is provided above a hanging bolt 18, which is rotated for its ascending, and the plate spring 17 is thereby pressed down for its horizontally pressedly spreading, and the right end of the plate spring 17 pushes out the engaging member 14 right to strongly fit the engaging part 12g of the hanging metal fitting body 12 and the tip 14a of the engaging member 14 in the right and left grooves 1c of the deck plate 1. Thus the hanging metal fittings are firmly attached to the floor of the deck plate.