PURPOSE: To efficiently make organic waste into compost by a smallsized simple device almost without adding a dried mixture by feeding a raw material from one end of container, introducing the raw material through an overflow wall close to the other side to an outlet while intermittent stirring, feeding air from the bottom of fermentation chamber to the container and positively ventilating space at the upper part of the container.

CONSTITUTION: A raw material feed opening 2 is equipped at one side of a container 1, a vertical wall 5 having given height is furnished at a sufficiently remote side from the feed opening 2 of the container 1, an overflow inlet 6 is made at the top of the vertical wall 5 and a fermentation chamber 7 is formed between the feed opening 2 and the vertical wall 5 in the container 2. Stirring pawls 10 and 11 of intermittent drive acting on almost the whole volume of the fermentation chamber 7 are equipped and a great number of air feed pipes 14 are dividedly set at the bottom of the fermentation chamber 7. Further, a collecting outlet 4 is furnished at the upper part of the container 1 at the further remote side from the vertical wall 5 and a ventilating fan 16 is connected and opened to space at the upper part in the container 1.