To provide a device used in the interior of a room, which is used in a sauna apparatus, for example, to promote healthy natural healing ability by using ore to generate negative ions and far infrared rays and applying heat to generate high humidity, thereby causing sweating of the human body by assistance of the air, and to provide the device used in the sauna device, rationalizing job site installation work and worked and manufactured in a factory to achieve high efficiency.

In this device, heat and resistance are applied to negative ion generating materials 13, 14 to generate humidity, negative ions and far infrared rays in the interior of a room, and the temperature in the room is made equal to those of the negative ions and high humidity to be absorbed in the body, so that perspiration can be caused even at low temperatures by the negative ions and far infrared rays.