PURPOSE: To extend a staying time of discharged gas within a heating chamber, perform a sufficient heating of the discharged gas and get a complete combustion by a method wherein a gas supplying pipe for taking discharged gas of a combustion furnace into the heating chamber is formed with a plurality of gas supplying holes, and a staying plate having a plurality of aeration holes therein is arranged within the heating chamber.

CONSTITUTION: Discharged gas discharged from ignited substances within an ascending or descending type batch ceramic baking furnace is fed to a gas supplying pipe 11 within a discharged gas disposal equipment 3 through a ceiling pipe 7 as well as a suction fan 6. The discharged gas fed from the gas supplying pipe 11 is injected from the gas supplying holes 14 and further uniformly fed into a chamber 15 of a heating chamber 9. The discharged gas fed into the chamber 15 flows in sequence into each of the chambers 16, 18 through the aeration holes 19 in the staying plate 12. Since positions of the aeration holes 19 in the opposing staying plates 12 are different from each other, the discharged gas is clogged by the staying plates 12, stayed in each of the chambers 15 and 18, and the discharged gas is efficiently and sufficiently heated by heat generated at the gas heater 13 so as to perform a positive and complete combustion there.