To eliminate the falling of garbage when a door is opened by providing an opening preparing operation means for outputting a driving control signal to rotate an impeller for a specified time or to a specified extent based on the judgement of a position inadequte to opening in the direction pushing down the garbage close to the front wall of a vessel to an impeller driving means.

Whether or not the upper face of the garbage close to the front wall of a garbage treating vessel is positioned at a position inadequate to opening (a position where the garbage falls off from a garbage inlet 4 when a door 4c is opened) above the lower edge 4b of the inlet 4 when a stop command signal is received is judged by an opening inadequateness judging means added to this stop controller. A driving control signal to rotate an impeller 2 for a specified time or to a specified extent in the direction pushing down the garbage close to the front wall of the vessel is outputted to an impeller driving means based on the above judgement by an opening preparing operation means. Consequently, the garbage never falls off from the inlet 4 even if the door 4c is opened.