NOVELTY - The method involves annealing CIGS multiple layers (30) to obtain a stoichiometric and homogeneous CIGS absorber layer. A cadmium or zinc sulfide layer (40) is deposited as a buffer material above CIGS layer. A zinc oxide layer and an indium tin oxides layer are sputtered onto surface of cadmium or zinc sulfide layer. Conductive silver paste is screen-printed on top of window layer (50) to form finger and bus lines. The completed rolls are cut into single solar cells for measuring conversion efficiencies and sorting completed solar cells into different groups.    USE - Manufacturing method for fabricating Copper indium gallium selenide (CIGS) thin film solar cells on conductive flexible substrate surface.    ADVANTAGE - The manufacturing process can be conveniently used to prepare the CIGS thin film solar cells with high efficiency and low cost. The CIGS thin film solar cells can be manufactured with power capacity as high as 30 MW per year if it is designed to run one meter wide flexible substrates with substrate delivery speed of one meter per minute. Uniformity of the evaporated films can be maintained. Since the inert atmosphere is very pure, material oxidation is avoided. Since the temperature is precisely controlled, non-uniform crystalline distribution is avoided. Thus inexpensive high quality thin film that will possess high competitiveness in the global photovoltaic market is achieved.    DETAILED DESCRIPTION - The method involves fabricating CIGS thin film solar cells from blank rolls of stainless steel or aluminum alloy foil to completed solar cells. Molybdenum layer having a niobium layer is deposited. Multiple layers of single copper, indium, gallium and/or selenium elements are electroplated. Selenium and a salt of sodium, potassium or lithium including sodium fluorite, potassium fluorite, and lithium fluoride, are vacuum-evaporated on surfaces of electroplated CIGS multiple layers.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the completed CIGS thin film solar cell prepared using the process.    Flexible substrate (10)    Back contact layer (20)    CIGS multiple layers (30)    Cadmium or zinc sulfide layer (40)    Window layer (50)