PURPOSE: To prevent offensive odor and leakage of sewage by providing both a dewatering means and a combustion means for burning substance after dewatering it.

CONSTITUTION: Garbage is cut and introduced into a dewatering basket 4 through an introduction part 5a and a cover 5 is put thereon and a motor 6 is rotated to rotate the dewatering basket 4 and it is dehydrated. After dehydrating, it passes through an upper passage port 19 by centrifugal force and falls on the hearth 22 of an adjacent combustion chamber 3. Thereafter the passage port 19 is closed by lowering a partition plate 21. A heater 23 and a reflector 24 are lowered and brought close to a dewatered garbage scraps A, and electricity is conducted through the heater 23. After drying them, the power of electricity conducted to the heater 4 is raised to burn the garbage scraps A, and thereby these can be easily treated in a short time.