Since raw water (W) is heated by a plurality of water pipes (10) before being supplied to a solar heat utilization device (2), the solar heat can be utilized effectively and it is advantageous in the aspect of cost as compared with a case where a reflector (1) is extended or upsized. Since a region (a) where the solar light (L) is shut out by the water pipe (10) and a region (b) irradiated with the solar light (L) passed through a predetermined clearance (B) between the water pipes (10) are formed on the ground surface (G), the quantity of sunlight received on the ground surface (G) can be controlled uniformly so that plants can be cultivated and domestic animals can be bred.
