Method of discharging gas from continuous oven and gas discharge structure

A to-be-burned object including a metal Si component or SiC or Si3N4 can 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 Si3N4 includes steps of 1) exhausting in-furnace gas including SiO vaporized during a burning process. An exhaust duct 2 used for this exhaust is provided at an upper part of a side wall 12 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 2 is guided to an exhaust pipe 3 connected to an outlet of the exhaust duct 2 at the outside of the furnace. This exhaust pipe 3 includes oxygen supply holes 31a and 31b. By sending oxygen supplied from an appropriate oxygen supply source into the exhaust pipe 3, SiO guided to the exhaust pipe 3 reacts with oxygen and is detoxified.