To provide a sun tracking light collector capable of smoothly rotating a mirror constituent even if sand or the like is mixed in a drive force transmitting means.

The drive force transmitting means for rotating the mirror constituent employs a chain block system composed of a chain constituted by alternately connecting oval rings vertically and horizontally, and a rotating block having a recessed portion engaged with the chain. The drive force transmitting means by the chain block system is used in a part for rotating the mirror constituent in the azimuth direction and a part for rotating the mirror constituent in the high altitude direction by an arm. As the chain block system is employed, the sand can be easily discharged from the chain and the recessed portion of the rotating block even if the sand is mixed therein, and the mirror constituent can be smoothly rotated even if it is used outdoors such as in a desert area. Furthermore, the chain block system is superior in maintenance since oil supply is unnecessary. Furthermore, the chain has large strength in the pulling direction, and transmits a high rotational drive force.