To make the charge of fresh kitchen garbage always possible and to discharge treated garbage easily by making the opening of a subordinate treatment tank communicate with the opening of a section part and with a main treatment tank through a shutter.

During treatment by a main treatment tank 10, when the operation is stopped, or before the treatment by the main tank 10, an empty subordinate treatment tank 20 is rotated to charge kitchen garbage, equipment and materials in the tank 20. The tank 20 is rotated with a shutter 80, and each opening 22, 85 of the shutter 80 and the tank 20 are bondingly stopped at the position of the opening 72 of a division part 70. At this moment, each opening 72, 85, 22 of the section part 70, the shutter 80, and the tank 20 are in agreement with each other. By the rotation of the blade part of the tank 10, the agitated kitchen garbage is placed into the tank 20 with a base material through each opening 72, 85, 22 of the division part 70, the shutter 80, and the tank 20 so that the diffusion of the garbage in the tank 10 can be prevented.