PURPOSE: To enable a rapid, hygienic and safe fermentation treatment and to accelerate composting by providing the above device with a fermentation tank for mixing microorganisms for composting org. waste at a natural ignition point or below and moisture and fat and oil-component control members and a control means for their supplying section and charging and discharging ports.

CONSTITUTION: Microorganisms, such as actinomycetes, which decompose and compost org. waste, such as crude refuse, at a temp. below the natural ignition point are used and rice bran, bean-curd refuse, oil cake, etc., to accelerate composing are used as the moisture and fat and oil-component control members. Agitating vanes 10 are mounted in the fermentation treatment tank 5 for executing the fermentation treatment. The treating device is provided with a deodorizing device to eliminate uncomfortable smells. A hot water jacket is mounted in the fermentation treatment tank 5 to constitute the tank in such a manner that the in-tank temp. is maintained at ≥60°C and below the natural ignition point. Further, the body of the crude refuse treating device 1 is provided with the charging port 2 for org. waste, an opening and closing mechanism for the discharging port of the crude refuse composed by the fermentation treatment and a control means 20 for controlling the microorganism supplying section and the control member supplying section.