Stainless steel foil with flattening film

A stainless steel foil with a flattening film, comprising,

• the stainless steel foil having a composition comprising stainless steel constituents and having a balance comprised of Fe and impurities,
• inclusions having particle diameter 2.00 μm or more comprising Al2O3:
• 30 mass % or less, with the exception of 0 mass %, and MgO:
• 10 mass % or less, with the exception of 0 mass %, with respect to a total mass of the particle diameter 2.00 μm or more inclusions,
• among the particle diameter 2.00 μm or more inclusions, the number of inclusions having particle diameter more than 5.00 μm present on the surface being 20/cm2 or less, and
• having a sheet thickness of 5.0 μm or more and 100.0 μm or less, and
• the flattening film having a film thickness of 0.3 μm or more and 5.0 μm or less on at least one surface of the stainless steel foil,
• wherein the flattening film is a silica-based organic-inorganic hybrid film, and the Si nuclei forming the organic-inorganic hybrid film include only T nuclei and Q nuclei.