Abstract: The object of the invention is a plane solar energy collector provided with multicellular transparent cover compound of adjoining juxtaposed identical cells wherein each cell is inscribed or formed inside a polygonal base frame and comprises a lenticonic elements i.e. having a substantially plane face, defined by a side of the said polygon, and by a bow-shaped curve, crossingthe two ends of the said side and, on the other hand, a convex transparent surface which connects the other sides of the base frame to the said curve.