PURPOSE: To additionally improve safety by constituting the safety mechanism in such a manner that a user does not suffer from a burn or low-temp. burn even in contact with the surface of a heating element base plate at the time of taking a sauna.

CONSTITUTION: This safety mechanism has the surface type heating element 8 on an enclosing wall body and is successively provided with a back surface plate, side plates and front surface plate collapsibly by this enclosing wall body. Further, the sauna heating room provided with a foldable chair therein is formed. A heat insulating plate 82 is placed on the rear surface side of the heating element base plate 81 and a safety sheet 83 formed into a desired mesh form of a synthetic resin which does not generate harmful gases even in combustion, is placed on the front surface side which is the flank surface of the sauna room. The surface type heating element 8 formed by coating the outside surfaces integrating these three members with flocked cloth on the flanks in the sauna room an integrating the surfaces, is used. As a result, the surface temp. of the cloth of the planar heating element is maintained at a low temp. and the burn is prevented.