To provide a fireproof panel fixture and a fireproof panel mounting structure using the fireproof panel fixture simple in structure and allowing a fireproof panel to be easily mounted in a short time.

The fireproof panel fixture 10 is composed of: a fixed plate 11 fixed to the fireproof panel 12; a support frame 15 integrally formed in square frame shape at the end of the fixed plate 11; a bolt 19 serving as a support shaft supported by the support frame 15 and extended in parallel to the fixed plate 11; and a movable plate 24 turnably supported by a cylindrical body 25 loosely fitted to the bolt 19, and mounted to a concrete floor material 22 serving as a structural skeleton of a building. The movable plate 24 is formed to take a vertical position along the fixed plate 11, and a horizontal position orthogonal to the fixed plate 11. When the movable plate 24 takes the horizontal position, the movable plate 24 is positioned abutting against a lower face 23a of a sidewall 23 of the support frame 15.