PURPOSE: To preclude the possibility of battens from vibrating themselves or being shifted their positions on account of being flapped by the wind or the like and consequently preclude the possibility of roofing material from being cracked by a structure wherein a collector and/or a heat accumulator are installed on the battens.

CONSTITUTION: Either the collector 1 to absorb solar heat only or both the collector 1 and the heat accumulator 6 to store the heat absorbed at the collector 1 are placed on a roof. In the solar heat utilizing device of the form as just mentioned above, at least either one of said collector 1 and heat accumulator 6 is installed on the battens 7. Owing to the installation on the battens 7 part, the roofing material is prevented from being broken down.