PURPOSE: To maintain the combustion conditions of combustion belts in good conditions by a method wherein the correcting range of objective speed of a stocker means is set so as to be larger than the correcting range of objective speed of the cast means of matters to be incinerated.

CONSTITUTION: The objective transporting speed of a stocker means and the throwing speed of the cast means 5 of matters to be incinerated are set by an objective speed setting means while the transporting speed of the stocker means and the throwing speed of the cast means 5 are regulated by a speed control means so as to achieve set objective speeds. Respective objective speeds are corrected based on the shifting condition of a past combustion rank with respect to a combustion rank including a present combustion temperature. In this case, the correcting range of objective speed of the stocker means is set so as to be larger than the correcting range of objective speed of the cast means 5. According to this method, sudden fluctuation of the amount of matters to be incinerated can be avoided and the combustion conditions of combustion belts 7-9, including fore section and aft section, can be maintained in good conditions.