To facilitate exchange of a member serving to rotatably support a stirring tool for stirring waste that is heated and baked in a disposal chamber provided in a heating chamber.

A rotary shaft 31 of a stirring tool 21 penetrates a disposal chamber 16 and a heating chamber 18 and protrudes its tip end to the outside of the heating chamber 18. The tip end and a coating member 35 for covering the neighborhood of the tip end are mounted detouchably on the rotary shaft 31 from the outside of the heating chamber 18, and the tip end of the rotary shaft 31 is rotatably supported on a member forming the heating chamber 18 through the coating member 35 with the aid of a stirring bearing 39 removable from the outside of the heating chamber 18. In such a construction, since the rotary shaft 31 is supported on the stirring bearing 39 through the coating member 35, the coating member 35 and the stirring bearing 39 are slid to cause weariness therebetween while the stirring tool 21 is rotated, but those members are detouchable from the outside of the heating chamber 18 so that they are easily exchanged even when they are worn.