To provide an atmosphere kiln enabling to stabilize the oxygen density of atmosphere inside a furnace at low level, saving injecting inert gas to little quantity and enabling the exchange or the cooling of the atmosphere in a short time.

Calcination is performed by arranging cylindrical muffles 4 piercing through the furnace walls 2 of a batch furnace and supplying atmosphere gas to the inside of the cylindrical muffles 4 only connecting the supplying pipes 6 and the exhausting pipes 10 of the atmosphere gas to the cylindrical muffles 4. Thermal storage mediums are accommodated to both edges of the cylindrical muffles 4 and taken out heat can be collected by the thermal storage mediums by changing the direction of supplying the atmosphere gas periodically.