A building panel has a deep drawn transparent film having an inner face and a structure having solar cells on the inner face of the deep-drawn film. The structure has an inner face turned away from the film and an outer face on or closely juxtaposed with the inner face of the film. A reinforcement layer constituted as a mass of foamed granular particles is spread over the inner face of the structure in direct contact with the inner face of the structure without the interposition of an adhesive and is heat cured to the film.