An apparatus for producing well-fermented compost by achieving an aerobic fermentation of organic wastes, excretion, etc. The apparatus comprises a fermentation vessel of a rectangular configuration, a device for feeding slurry-like organic wastes within the base compost which has been piled in the vessel and for stirring the base compost and the slurry-like organic wastes, and a device for gathering an upper portion of the predetermined thickness of the fermented compost and for carrying the gathered compost out of the vessel. These devices are movably positioned on the top of the vessel.
