A separator material for a fuel cell is provided, in which a uniform first Au-plated layer having a thickness of 0,5-4 nm is formed on one surface of a metal thin plate and a uniform second Au-plated layer having a larger thickness than that of the first Au-plated layer is formed on the other surface of the metal base material, wherein the covering rate of each of the cross-sections of the first Au-plated layer and the second Au-plated layer is 80% or more as observed on a transmission electron microscope. The separator material can have excellent corrosion resistance even when the thicknesses of the Au-plated layers formed on the surface of the base material are small, and can be produced at reduced cost. Further provided are: a separator for a fuel cell and a fuel cell stack, each of which is produced using the separator material.