A thin-film solar battery is constructed such that it includes a translucent insulating substrate, a first transparent conductive film formed of a crystalline transparent conductive film on the translucent insulating substrate, with an uneven structure on a surface thereof, a second transparent conductive film formed of a transparent conductive film on the first transparent conductive film, with an uneven structure on a surface thereof, where the uneven structure is more gentle than the uneven structure of the first transparent conductive film, a power generation layer formed on the second transparent conductive film and having at least one crystalline layer to generate power, and a backside electrode layer formed of a light-reflective conductive film on the power generation layer. A substantially convex hollow portion projecting from the translucent insulating substrate is provided between adjacent convex portions in the uneven structure of the first transparent conductive film.