PURPOSE: To prevent sunlight from reflecting in the same direction by providing a recessed part and/or a projection part on the front side and/or the rear side of a light-transmitting glass.

CONSTITUTION: A light-transmitting glass 1 consisting of for instance, soda quartz glass or the like is arranged on the front side of a solar battery element 2. A circular projection part 1a is formed on the front side of light-transmitting glass 1. The projection part 1a is so formed for instance, that a diameter of the circle may be 3mm and a pitch may be about 7mm. In this way, when the circular projection parts 1 are formed covering nearly the whole surface of the light-transmitting glass, reflection light is scattered even if sunlight irradiates this light-transmitting glass 1. Accordingly, sun light is prevented from reflecting in the same direction.