Disclosed is a hanger assembly that can be used stably over a long period of time. Specifically disclosed is a hanger assembly for hanging up a firebrick that forms the ceiling surface in the float bath roof of a float bath device for a device for producing float plate glass characterized in that at least part of the hanger assembly is composed of silicon nitride, and that the silicon nitride does not contain alumina (Al2O3) and silica (SiO2) substantially and contains yttria (Y2O3).