A stainless steel having good conductivity and ductility for use in a fuel cell separator is provided. In particular, the stainless steel has a composition of, in terms of % by mass, C: 0.01% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.02% or less, Cr: 20 to 40%, Mo: 4.0% or less, and at least one selected from Nb, Ti, and Zr: 0.05 to 0.60% in total, the balance being Fe and unavoidable impurities. At least one precipitate having an equivalent circle diameter of 0.1 μm or more is present per 100 μm2, a ratio of a thickness t (μm) to a maximum diameter Dmax (μm) of the precipitates satisfies formula (1) below 20≦t/Dmax  (1) and the thickness is 200 μm or less.