To provide a temperature and humidity controlling method and so forth for a healthy sauna apparatus which realizes an always optimal bathing temperature and a relative humidity by a fully automatic method, and by which various kinds of bathing sensations can be obtained.

A temperature and humidity controlling cycle comprising an intermediate temperature holding period PL, a forcible temperature raising period PH, and a humidifying period PW is repeatedly performed. In this case, in the intermediate temperature holding period PL, the thermal output of a heating device is controlled by a temperature controlling device, and a temperature in a sauna chamber is kept at a temperature from 60°C to 110°C. The forcible temperature raising period PH is provided right after the intermediate temperature holding period PL, increases the thermal output of the heating device regardless of the control by the temperature controlling device, and forcibly raises the temperature in the sauna chamber in a temperature range from 5K to 20K. The humidifying period PW operates a humidifying device in a specified time from the final stage of the forcible temperature raising period PH to the initial stage of the intermediate temperature holding period PL.