PURPOSE: To secure a high heat collecting efficiency throughout the year by a method wherein a solar heat collector and the frame for fixing the solar heat collector are connected to each other with two pairs of support rods of different lengths in such a manner that the support rods are held rotatable with respect to the solar heat collector and the frame.

CONSTITUTION: One end of each of a pair of support rods 3 and one end of each of a pair of support rods 4 are rotatably fixed to a solar heat collector 1 and the other ends of both of the support rods 3 and 4 are rotatably fixed to a frame 2 so that a linkage mechanism is formed of the solar heat collector 1, the frame 2, the support rods 3 and the support rods 4. Numeral 5 designates a drive device for turning the pair of support rods 3 up and down and numeral 6 designates a solar battery. When the pair of support rods 3 are turned to rise up by the drive device 5, it is possible to make the angle of inclination of each of the support rods 3 at about 10°. In other words, assuming that the angle of inclination of the roof is, for example, 30°, it is possible to change continuously the angle of inclination of the heat collecting surface of the heat collecting device in the range of 20W45°.