To provide a fireproof window for improving a fireproof function by surely performing heat blockage on the periphery of fireproof window glass by completely blocking flames at the fireproof window glass by providing a plurality of followings of heat blockage functions to the flames at the fireproof window glass.

The fireproof window is constituted so as to check the propagation of the flame to the indoor side from the outdoor side by juxtaposing outside glass facing the outdoor side and inside glass facing the indoor side on the inner periphery of a frame body, and has a fireproof glass body constituted so that the inside glass is composed of multiple glass composed of heat resisting glass, and a heat insulating gas layer is formed between the outside glass and the inside glass, and the inside glass is characterized by arranging a heat insulating layer between a plurality of sheets of glass.