Abstract: In the agitation chamber (11), the human waste and the flush water from the flush toilet (20) are mixed. A heat accumulator (12) is provided in the discharge path of the exhaust gas. The drying chamber (13) heats the discharge from the agitation chamber (11) using the heat of the heat accumulator (12). The moving device (18) moves the scraper (16) and the suction port of the suction device (17) in the drying chamber (13). The scraper (16) scrapes off the residual human waste stuck in the drying chamber (13). The suction device (17) suctions the residual human waste in the drying chamber (13). The water accumulation chamber (14) recovers the water vapor from the drying chamber (13). The recovered water is transported by the pump (15) to the flush tank (30) for the flush water, and thus recirculated. The space for holding the flush water can be reduced.