To provide a thin-film solar battery module that prevents the light incidence surface of a reflection prevention film from being contaminated easily, and from which the adhered contamination can be easily removed.

In the solar battery module, a reflection film that is mainly made of silica and has an irregular surface having a step of 0.01-1 μm is deposited on a light reception surface. In the solar battery module, a contamination prevention agent containing silicone oil as a main constituent is applied to the surface of the reflection prevention film. The contamination prevention agent preferably contain a fluorine compound, especially a compound that is obtained by crosslinking silicone oil and liquid fluorocarbon is desirable.