A method of burning exhaust gases containing gaseous silane in which the exhaust gases containing gaseous silane to be introduced into a combustion chamber are diluted with an inert gas so that the concentration of silane gas is reduced to less than 30% by volume and the diluted exhaust gases are fed from a nozzle to the combustion chamber and burnt through reaction with airs in the combustion chamber while the region between the head of the nozzle top end and the base portion of the burning flame is shielded with an inert gas atmosphere. An inert gas mixing pipe 17 is connected for dilution to an exhaust gas feed section 16, an enclosure pipe 21 is fitted to the outer circumference of an exhaust gas introduction pipe 13 introduced into the combustion chamber 6 to constitute a double pipe structure, and the enclosure pipe 21 is connected at the rear end thereof to an inert gas feed pipe 25 and slightly protruded at the top end thereof ahead of the top end of the exhaust gas introduction pipe.