Integrated thin-film solar cell and process for producing the same

A problem of the invention is to prevent a substrate from being damaged with a metal stylus upon mechanical patterning. In the invention, a thin film obtained by accumulating in this order a substrate 2 , a back surface electrode layer 3 , a multi-element compound semiconductor thin film (light absorbing layer) 5 , a transparent buffer layer 6 having a high resistance and a transparent and electroconductive window layer 7 is divided into respective unit cells, which are connected plurally in series to obtain a prescribed voltage, and it contains patterning P 1 of dividing the back surface electrode layer 3 , patterning P 2 of dividing the light absorbing layer 5 , or the light absorbing layer and the buffer layer 6 , and patterning P 3 of dividing from the window layer 7 up to the light absorbing layer 5 , in which in P 2 and P 3 , an ultrathin film layer 4 formed secondarily through reaction with a chalcogen element on the surface of the back surface electrode layer 3 in the formation step of the light absorbing layer is used as a solid lubricant upon mechanically removing the constitutional thin film layers with a metal stylus to form grooves.