Sollar collector

Patent Granted PROBLEM TO BE SOLVED: To provide a thin and fixed solar collector, capable of converging light taken into the inside on an end surface at high efficiency, and responding to a wide range of incident angle change, and a solar battery and a solar heat collector using it. ; SOLUTION: In this solar collector, a light guide plate 1 having a reflecting surface 3 applied onto the lower surface thereof is disposed under at least one thin film-like optical functional sheet 2 capable of permitting incident light of a wide angle [theta]<SB>1</SB>from the upper surface side and radiating it to the lower surface side, whereby the incident light of the wide angle [theta]<SB>1</SB>is incident on the light guide plate 1 via the optical functional sheet 2, and efficiently converged to at least one end surface 1a of the light guide plate 1 by light closing effect by total reflection and diffraction within the light guide plate and the reflecting effect on the reflecting surface 3 applied to the lower surface 1b of the light guide plate 1.