To prevent malodor from being produced.

There are provided a burner combusting odorous components by being forcedly supplied with combustion air, an odor air combustion chamber for heating and decomposing odor air, a conversion means for converting air supplied from a high temperature air supply fan to garbage drying high temperature air using burner combustion heat, a drying processing part 1 for drying garbage, a temperature sensor 10 for detecting temperature in the drying treatment part 1, and a revolution reduction means for reducing the number of revolutions of the high temperature air supply fan when the temperature sensor 10 detects a predetermined temperature. For this, water is reduced at a later stage of the treatment, and hence when the temperature sensor 10 detects a predetermined temperature, the amount of the odor air is reduced and the temperature in the odor air combustion chamber becomes high, and further since the odor components are also reduced, the odor components are surely decomposed.