Abstract: An improved method and apparatus for incinerating successive batches of waste material are provided wherein each batch is introduced into a primary combustion zone and substochiometrically combusted with air introduced therein, the combustion gases produced in the primary combustion zone are conducted to a secondary combustion zone wherein they are combined with secondary air and further combusted and the combustion gases produced in the secondary combustion zone are withdrawn therefrom. By the present invention, the rate of secondary air combined with the combustion gases in the secondary combustion zone is controlled to maintain the combustion gases withdrawn therefrom at a substantially constant selected temperature level during the peak incineration stage of each waste batch.