Stainless steel substrate for solar cell having superior insulating properties and low thermal expansion coefficient and method of producing the same

A stainless steel substrate for a solar cell having superior insulating properties and a low thermal expansion coefficient, the stainless steel substrate comprising:

• stainless steel which contains, by mass %,
• Cr:
• 9% to 25%,
• C:
• 0.03% or less,
• Mn:
• 2% or less,
• P:
• 0.05% or less,
• S:
• 0.01% or less,
• N:
• 0.03% or less,
• Al:
• 0.005% to 5.0%,
• Si:
• 0.05% to 4.0%, and
• a remainder including Fe and unavoidable impurities, satisfies one or both of Al content is 0.5% or more and Si content is 0.4% or more, and satisfies the following expression (1);
• and
• an oxide film formed on a surface of the stainless steel, the oxide film containing (i) Al2O3 in an amount of 50% or more or containing (i) Al2O3 and (ii) SiO2 in a total amount of 50% or more,
• Cr+10Si+Mn+Al>24.5 (1)
• where a symbol of each element in the expression (1) represents the amount (mass %) of the element in the steel, wherein the oxide film contains (iii) Mg Al2O4.