NOVELTY - A barrier layer (32) containing a nitride film is formed on a mica substrate (31). A metal film as reverse side electrode and an optical absorption layer (34) are then formed. An n-type buffer layer (35) is formed on the optical absorption layer. A transparent electrode layer (36) is formed on the buffer layer. A scribing process (III) divides the element formed on the transparent electrode, and a thin film solar cell is manufactured.    USE - For power generation.    ADVANTAGE - The method forms chalcopyrite-type thin film solar cell having high conversion efficiency, surface smoothness and reduced weight, with high productivity. The method is inexpensive, improves adhesion between electrode with respect to substrate.    DETAILED DESCRIPTION - A mixture of resin and mica is baked, ground and formed into an elongate winding type substrate (31). The substrate is supplied to dry cleaning process where the substrate is cleansed by plasma ashing. A barrier layer (32) containing a nitride film is formed on the substrate. A metal film is formed as a reverse side electrode (33), which is divided by scribing process (I). A precursor containing copper, indium and gallium is formed on the reverse side electrode. Selenium is added into the precursor. An optical absorption layer (34) containing I, III and VI group elements, is then formed and heat processed. An n-type buffer layer (35) is formed on the optical absorption layer. A scribing process (II) divides the element formed at each process. A transparent electrode layer (36) is formed on the buffer layer as upper electrode. A scribing process (III) divides the element formed on the transparent electrode layer, and a thin film solar cell is manufactured. A surface smooth layer containing silicon nitride or silica is formed between the cleaning process and barrier layer formation process.    DESCRIPTION OF DRAWING(S) - The figure shows laminate structure of thin film solar cell. (Drawing includes non-English language text).    substrate (31)    barrier layer (32)    electrode layer (33)    optical absorption layer (34)    buffer layer (35)    transparent electrode layer (36)