A high temperature gas reforming cyclo-incinerator, using reformed water and strongly swirling inlet air in its interior to burn up wastes. The incinerator has a dust collecting structure designed to almost completely remove circulating dust and other harmful impurities from air strongly swirling in the incinerator and discharge clean air to the atmosphere. Internal and external lower tubs have substantially larger diameters than those of internal and external upper tubs, thus effectively burning up a large quantity of wastes at one time. The incinerator is also provided with a flow rate control fan unit separate from a main fan unit, thus controlling the amount of inlet air as desired and allowing a user to control the incineration rate of wastes in the incinerator.