A ferritic stainless steel suited for use as a member for heat exchangers to be brazed with Ni-based filler metal or Cu-based filler metal, comprising, on the basis of mass percent, C: 0.03% or less, Si: 3% or less, Mn: 2% or less, P: 0.05% or less, S: 0.03% or less, Cr: from 11 to 30%, Nb: from 0.15 to 0.8%, and N: 0.03% or less, wherein the balance is composed of Fe and incidental impurities, and wherein a value A determined by the following equation is 0.10 or greater: A = Nb - (C×92.9/12 + N×92.9/14).