PURPOSE: To efficiently execute a treatment of excretions with a simple and small-sized device by mixing the excretions and excretion decomposing bacterium-contg. moisture control materials, then blasting hot air to the mixture and circulating hot water, thereby gradually lowering the moisture of the excretions and the mixture.

CONSTITUTION: A prescribed amt. of the excretions are first charged into a fermentation tank section 4 and are mixed with the previously charged excretion decomposing bacterium-contg. moisture control materials as bed materials to lower the moisture to about 60%. Next, hot air is blasted for the prescribed time to the mixture in the fermentation tank section 4 to evaporate the moisture and to lower the moisture to about 50%. In succession, hot water is circulated from a hot water boiler 4A2 to a hot water pipes 4A1 extended around the side faces and bottom of the fermentation tank section 4 to maintain the temp. of the mixture within a range of 45 to 55°C and to lower the moisture down to about 35%. The prescribed amt. of the mixture is left as the moisture control material for the next time and thereafter the amt. exceeding the prescribed amt. is taken out of the discharge port of a fermentation tank body 6.