Abstract: An incinerator plant is provided having a primary and secondary incinerator and a combustion furnace connected thereof, the incinerators having a cooling chamber filled with cooling water which is formed between the bottom plate and a partition wall plate, with the combustion chamber formed above the bottom plate. A fan chamber is formed under the partition wall plate and connected to the combustion chamber by a draft tube installed through the bottom plate and partition wall plate so that outside air fed in to the fan chamber flows in to the combustion through the draft tubes, and the bottom plate which has become hot will be cooled by cooling water in the cooling chamber. Gases produced from the incinerator are passed into the combustion chamber which is adapted to burn combustion gases generated in the primary and secondary incinerators.