To activate the metabolism of even a weak person in a short time with relaxation and without anxiety by providing the seat surface and the seat back surface of a chair attached with a seat back in a sauna compartment with a sheet-shaped heat generating heaters which are coated with a heat-proof film and executing energizing and heat generating.

The chair with the seat back arranged inside the sauna compartment 1 is constituted of the seat back part 8, both armrest parts 9, a sitting part 10 and foot rest part 11. The sheet-shaped heat generating heater parts 13a and 13b are respectively disposed on the seat back surface 8a and the seat surface 10a. The sheet-shaped heat generating heater parts 13a and 13b are constituted by coating a heat generating body 14 with a heat insulating heat-proof film 15 and heat is generated by energizing. The heaters 13a and 13b can be arranged in the center parts of respective arrangement parts or in the center parts. Then, automatic control or manual control is executed. Thus, internal activation is attained in a relaxation state without anxiety in a clean room.