PURPOSE: To eliminate users' unpleasant feeling of coldness in winter owing to the intrusion of cold outdoor air caused by the negative pressure in a room by supplying or discharging a hot exhaust gas that is generated by incinerating wastes and the outdoor air at the same time and exchanging heat between the exhaust gas and the supply air.

CONSTITUTION: An exhaust gas that is cleaned by a catalyst is blown into an exhaust gas fan 10 from an exhaust gas channel 6, and then it goes through the exhaust gas channel of a heat exchanger 9 and is discharged to the outdoor. At the same time as the gas discharge to the outdoor the outdoor air is blown into an air supply fan 11 through a supply air channel of the heat exchanger 9 and goes through a supply air channel 13 and is discharged from a supply air port 14 into a kitchen. At this time the heat energy possessed by the exhaust gas is recovered by the outdoor air that is supplied in the heat exchanger 9, and the room temperature is raised by the supply air to the inside of the room to exhibit room heating effect. Further, it eliminates the inconvenience that the pressure in the room becomes negative with respect to the outside of the room, that cold air intrudes into the room by the consumption of the indoor air for the discharge of the exhaust gas and for the combustion and that the user feels coldnexs.