NOVELTY - The thin-film solar cell comprises transparent substrate (1) onto which a structured layer (2) having a periodical pattern of elevations and/or depressions is applied, layers including a front electrode layer (3), a semiconductor layer (4) and a backing electrode layer (12) deposited onto the structured layer one by one. The structured layer is produced by embossing or printing a layer, which is produced according to sol gel method. The structured layer has refractive index greater than the refractive index of the substrate and not more than the refractive index of the front electrode layer.    USE - Used as thin-film solar cell.    ADVANTAGE - The thin-film solar cell can be economically manufactured with reduced thickness and improved efficiency.    DETAILED DESCRIPTION - The thin-film solar cell comprises a transparent substrate (1) onto which a structured layer (2) having a periodical pattern of elevations and/or depressions is applied, layers including a front electrode layer (3), a semiconductor layer (4) and a backing electrode layer (12) deposited onto the structured layer one by one. The structured layer is produced by embossing or printing a layer, which is produced according to sol gel method. The structured layer has a refractive index greater than the refractive index of the substrate and not more than the refractive index of the front electrode layer. The structured layer is formed through a glassy hybrid polymer, nanocrystalline and/or partially crystalline metaloxide- and/or semiconductor oxide network. The distance between the elevations and/or depressions of adjoining periodical pattern is 600 nm. The backing electrode layer has a transparent backing electrode sub-layer on its side turned to the semiconductor layer. The transparent substrate is made of glass or glass ceramics and the front electrode layer is made of zinc- or zinc oxide. The refractive index of the structured layer is 1.6-1.8. A diffusion barrier is deposited below or above the structured layer. The thin-film solar cell has a pn-transition. The average layer thickness of the structured layer is 20 mu m. The periodical patterns are modulated in sub micrometer-range on periodical pattern structure formed through elevations and/or depressions with an interval between the elevations and/or depressions of 1 mu m. The periodical patterns are formed in sub micrometer-range and/or the modulated periodical pattern structure. The aspect ratio of the elevations and/or depressions in sub micrometer range and/or the elevations and/or depressions of the modulated pattern structure is 0.01-2. The semimetal oxide is silicon dioxide and the structured layer consists of transparent metal oxide. The portion of organic components in the structured layer is 5 mass%. The silicon- and/or silicon organic component is photochemically polymerisable. The structured layer is produced with a photochemical hardening process and subsequent thermal decomposition of organic components so that the portion of the organic component in the structured layer is 5 mass%. The structured layer is applied on glass as substrate and is thermally treated at 300 degrees C. The semiconductor layer consists of silicon based semiconductor or a compound semiconductor. An INDEPENDENT CLAIM is included for a method for the production of thin-film solar cell.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a thin-film solar cell.    Transparent substrate (1)    Structured layer (2)    Front electrode layer (3)    Semiconductor layer (4)    Backing electrode layer. (12)