NOVELTY - A silicon group electric power generation layer (13) is formed on surface side electrode layer (12) of a transparent substrate (11). A process liquid is contacted with surface of electric power generation layer, and a back surface side transparent electrode layer (14) is formed on electric power generation layer by wet method to manufacture solar cell. The process liquid contains mixed solvent of water, aqueous solution and organic solvent or mixed solvent of water and organic solvent.    USE - Manufacture of solar cell.    ADVANTAGE - The solar cell having improved conversion efficiency is economically manufactured. The contact resistance of electric power generation layer and transparent electrode layer is reduced. The work function of electric power generation layer is improved.    DETAILED DESCRIPTION - A silicon group electric power generation layer is formed on surface side electrode layer of a transparent substrate. A process liquid is contacted with surface of electric power generation layer, and a back surface side transparent electrode layer is formed on electric power generation layer by wet method to manufacture solar cell. The process liquid contains mixed solvent of water, aqueous solution and organic solvent or mixed solvent of water and organic solvent. The contact processing is carried out using 10-70 degrees C water for 0.5-1440 minutes, when solvent is water. The contact processing is carried out using 0-60 degrees C aqueous solution for 0.5-280 minutes, when solvent is aqueous solution. The contact processing is carried out using 10-50 degrees C organic solvent for 0.5-1440 minutes, when solvent is organic solvent. The contact processing is carried out using 25-50 degrees C mixed solvent for 5-720 minutes, when solvent is mixed solvent.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view explaining manufacture of solar cell. (Drawing includes non-English language text)    Transparent substrate (11)    Surface side electrode layer (12)    Electric power generation layer (13)    Back surface side transparent electrode layer (14)    Back surface side reflecting electrode layer (16)