STRUCTURE OF FURNACE

PROBLEM TO BE SOLVED: To obtain a furnace body that can quickly raise temperature due to a sufficient insulation property, stably maintains a high-temperature state, and at the same time has sufficient strength and compact design even when adopting ceramic fiber formed on a peripheral wall with relatively low density. SOLUTION: In the structure of a furnace that introduces flame from a pilot burner for setting the inside of a furnace body to a high-temperature state, double-structure furnace wall members 4 (4A and 4B) and furnace lid members 6 (6A and 6B) are composed by a thin-plate-shaped lightweight fireproof material where ceramic fiber is formed. A reinforcing member 5B where a metal material with a narrow diameter is assembled in a net shape is provided between the double-structure furnace wall member 4 and the furnace lid member 6, at the same time, radiant heat reflection member 5A formed as a thin leaf body consisting of the metal material is provided between the double-structure furnace wall member 4 and the furnace lid member 6 and at the same time inside the furnace body of the reinforcing member 5B. Then, a ceramic fireproof curing agent 7 consisting of the ceramic fiber formed in a cotton shape is made on the inner surface of the furnace body at least in the double-structure furnace wall member 4 and the furnace lid member 6.