To effectively dry a treating object in a short time when drying the treating object.

The method includes a first process for storing garbage G as an example of the treating object in a rotatable container 5 and introducing the warm air into the container 5 in the state of stopping rotation of the container 5 and drying the garbage G exposed to the surface when drying the garbage G by introducing warm air into the container, a second process for newly exposing the garbage G containing water to the surface by rotating the container 5 after that, and a third process for stopping rotation of the container at the point of time when the garbage G containing water is exposed to the surface and drying the garbage G newly exposed to the surface, and these processes are repeated. Further, as the need arises, the garbage G is stirred by a stirring blade 23.