To provide a drying device and method of a space saving type utilizing natural energy effectively and suitable for drying a small quantity of moisture- containing substance, and to suppress the discharge of malodor and harmful substances due to drying.

There are provided a drying device along with a method therefor characterized by having a moisture-containing substance-accommodating member 10 for accommodating a moisture-containing substance 30 heated by a heat source and a moisture permeation, and suppressant for moisture permeation and aeration 20 having an evaporative cooling surface 20A and a condensing surface 20B on which steam evaporated from the moisture-containing substance 30 is condensed. The suppressant for moisture permeation and aeration 20 has a water-impermeable plate 22 and a permeating member 24. The water condensed on the condensing surface 20B is guided to the evaporative cooling surface 20A.