To inexpensively provide a mechanical stoker type waste incinerator which can be made to make stable combustion by promoting the drying and combustion of waste.

This mechanical stoker-type waste incinerator, having an intermediate ceiling 8, is provide with a means which circulates part of the main flue gas to the upstream side in the incinerator. Preferably, the means is provided with a pipeline 20 for circulating the gas, a heating mean 23 installed to the pipeline 20, and a dust remover 21 and a blower 22, installed midway of the pipeline 20. Alternatively, a gas circulating pipeline laid in the internal wall of the incinerator or heat-resisting bricks constituting the internal wall can be used as the means for circulating part of the main flue gas. In addition, it is preferable to install a pulsating flow generating device to the gas-circulating pipeline.