NOVELTY - A solar cell substrate material (1) made from stainless steel foil (2) is manufactured by performing thermal pretreatment on 20-200 mu m thick stainless steel foil for stress relief at 250-1050 degrees C in atmosphere consists of nitrogen (N2) gas, hydrogen (H2) gas, argon (Ar), AX gas, and/or HN gas, wherein stainless steel foil contains 7-40 mass% chromium (Cr) and has wire expansion rate at 0-100 degrees C of less than or equal to 12x 10-6/ degrees C, forming back surface electrode (5) consists of molybdenum (Mo) layer on surface of thermally pretreated stainless steel foil, and forming light absorption layer (4).    USE - A manufacturing method of solar cell substrate material made from stainless steel foil (claimed).    ADVANTAGE - Stainless steel foil is cheap, prevents peeling of light absorption layer from solar cell substrate material, and can be mass-produced, and sunlight conversion efficiency is improved.    DETAILED DESCRIPTION - A solar cell substrate material (1) made from stainless steel foil (2) is manufactured by performing thermal pretreatment on 20-200 mu m thick stainless steel foil for stress relief at 250-1050 degrees C in atmosphere consists of nitrogen (N2) gas, hydrogen (H2) gas, argon (Ar), AX gas, and/or HN gas, wherein stainless steel foil contains 7-40 mass% chromium (Cr) and has wire expansion rate at 0-100 degrees C of less than or equal to 12x 10-6/ degrees C, forming back surface electrode (5) consists of molybdenum (Mo) layer on surface of thermally pretreated stainless steel foil, and forming light absorption layer (4) which performs film formation heat processing and consists of copper indium gallium selenide (Cu(In1-xGax)Se2) on back surface electrode. An INDEPENDENT CLAIM is included for a solar cell substrate material (1) made from stainless steel foil (2).    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional diagram of a solar cell substrate material made from stainless steel foil.    Solar cell substrate material made from stainless steel foil (1)    Stainless steel foil (2)    Light absorption layer (4)    Back surface electrode (5)