To perform drying processing of garbage and used diapers with high volume reduction effect by a compact and inexpensive device while sufficiently deodorizing and sterilizing them.

A process for heating a heating medium 6 while passing through an internal electric heating tube 4, releasing and filling the same in the treatment chamber 3, and discharging the same to the outside of the treatment chamber 3 while being exposed to the treated object 1, is performed for a prescribed time in accompany with the generation of radiation heat 5 by heat generation by distributing electric power to the internal electric heating tube 4 disposed in the treatment chamber 3 receiving the treated object 1 in a state of applying radiation heat 5 to the treated object 1 from a very close place, and the treated object 1 is dried while being sterilized and deodorized.