Method of discharging gas from continuous oven and gas discharge structure

34 34 a bA to-be-burned object including a metal Si component or SiC or SiNcan be burned in such a manner that vaporized SiO can be safely exhausted without causing SiO attached to a wall of a furnace or an inner face of an exhaust duct. An exhaust method of a continuous furnace for continuously burning a to-be-burned object containing a metal Si component or highly-fire-resistant SiC or SiNincludes steps of 1) exhausting in-furnace gas including SiO vaporized during a burning process. An exhaust duct used for this exhaust is provided at an upper part of a side wall of the furnace having a higher temperature (1300 degrees C. or more) than a concentration temperature of SiO vaporized during a burning process. 2) oxidizing the exhausted SiO at the outside of the furnace to detoxify SiO. The in-furnace gas exhausted by the exhaust duct is guided to an exhaust pipe connected to an outlet of the exhaust duct at the outside of the furnace. This exhaust pipe includes oxygen supply holes and . By sending oxygen supplied from an appropriate oxygen supply source into the exhaust pipe , SiO guided to the exhaust pipe reacts with oxygen and is detoxified.