Ferritic stainless steel foil for solar cell substrate

A method for manufacturing a ferritic stainless steel foil for a solar cell substrate, the method comprising:

• annealing a ferritic stainless steel sheet having a chemical composition comprising Cr:
• 14% or more and 18% less, by mass %;
• then cold rolling the steel sheet with a rolling reduction in the range of 60% or more to obtain the ferritic stainless steel foil;
• and
• subsequently heat treating in an inert gas atmosphere in such a manner that (i) steel foil is heated to a heat treatment temperature T(° C.) at a heating rate in the range of 10° C./s or more and 100° C./s or less, (ii) the steel foil is held at the heat treatment temperature T (° C.) for a duration in the range of 1 second or more and 60 seconds or less, and (iii) the heated steel foil is cooled at a cooling rate in the range of 5° C./s or more and 50° C./s or less,
• wherein the heat treatment temperature T (° C.) satisfies relational expressions (1) and (2) in accordance with a temperature X of a substrate in an optical absorber layer growth process selected from a temperature in the range of 450° C. or higher and 600° C. or lower:
• when 450° C.≦X<500° C., 300° C.≦T≦750° C. (1)
• when 500° C.≦X≦600° C., X−200° C.≦T≦750° C. (2).