ABSTRACT OF THE DISCLOSURE A controlled air incinerator having an increased capacity fox burning waste material and having increased efficiency for completely burning all burnable waste material fed there-to. The controlled air incinerator, which is sometimes re-ferred to as a "starved air" incinerator, requires accurate control of burning conditions so as to provide at all times a discharge of clean flue gases free from pollutants. In the present incinerator, means are provided for transferring the waste material therethrough while burning, the means causing the burning waste material to tumble within the combustion chamber and open up so as to expose to combustion air any unburned but burnable parts of the waste material whereby the oxygen of the combustion air will result in complete combustion. The incinerator system is essentially completely automatic in that the combustion chamber of the system may be loaded without changing burning conditions in the combustion chamber and the waste material loaded therein is progressively moved through the combustion chamber while burning from the inlet end to the discharge end by transfer means, the movement of the burning waste material resulting in more complete combustion. The system further has means for automatically discharging products of combustion, such as ash, from the outlet end of the combustion chamber without disturbing the burning conditions within the combustion chamber.