NOVELTY - Organic substance residue fermentation decomposition device (1) has a watertight container (2) in which an organic substance residue (16) is held by a habitation floor (15). An agitator carried by a moving element that moves in the oblong hand direction (53) of the container on rails mounted inside the container, stirs the organic substance residue held on the habitation flooring by moving in the oblong hand direction.    USE - For performing the fermentation decomposition of an organic substance residue such as foodstuffs residue, livestock dung, etc., by using microorganisms such as anaerobic bacteria.    ADVANTAGE - The organic substance residue maintained by the habitation flooring can be stirred from end-to-end inside the watertight container by an agitator which can be moved on top of rails along the oblong hand direction of the container. The power requirement of the agitator can be made small. The fermentation decomposition of the organic substance residue can be promoted by the compound control action of moving the agitator and habitation flooring along the oblong hand direction of the container.    DETAILED DESCRIPTION - Organic substance residue fermentation decomposition device (1) has a watertight container (2) in which an organic substance residue (16) is held by a habitation floor (15). An agitator carried by a moving element that moves in the oblong hand direction (53) of the container on rails mounted inside the container, stirs the organic substance residue held on the habitation flooring by moving in the oblong hand direction. The container is formed by joining a number of container units divided in the oblong hand direction watertightly, and is made airtight and maintained at a negative pressure internally by a decompression device (101). A controller (39) is used for performing the operation control of the decompression device to switch the interior of the container to a normal pressure or a positive pressure or negative pressure.    DESCRIPTION OF DRAWING(S) - The figure shows outline block diagram of the entire composition of the organic substance residue fermentation decomposition device.    organic substance residue fermentation decomposition device (1)    watertight container (2)    habitation floor (15)    organic substance residue (16)    controller (39)    oblong hand direction (53)    decompression device (101)