To allow a room temperature to be adjusted with a simple structure by a temperature-sensitive body by changing it to first, second and third states as the room temperature becomes a low, an intermediate and a high temperature.

Temperature-sensitive bodies 14, 24 begin to protrude rods 15, 25 at approximately 15°C and 23°C respectively by thermal expansion of wax, have the rods protruding by the maximum amount at approximately 22°C and 30°C, and have the rods protruding no more even if the temperature rises higher. At the time of a low temperature of approximately 15°C or lower, the rods 15, 25 do not protrude, when a retainer 21 is pressed by a spring 23 to be positioned backmost with the minimum front protrusion of a shaft 22. At an intermediate temperature of approximately 22°C, the rod 15 stops protruding, when a stopper 27 functions so that the retainer 21 is positioned at the front-most part with the maximum front protrusion of the shaft 22. At a high temperature of approximately 30°C or higher, the rod 25 stops protruding, when the retainer 21 is positioned backmost with the minimum front protrusion of the shaft 22. When an air duct switch valve is coupled to the shaft 22, air can be led into a room at high and low temperatures while air can be led to under the roof at an intermediate temperature.