Abstract: A separator for use in a fuel cell having a fluoric synthetic resin within the pores of a separator base which makes the separator impermeable to reformed fuel and air. A process for manufacturing such a separator is also provided wherein the pores of the separator base are impregnated with fluoric synthetic resin, the base in dried, excess resin is removed from the base, and the resin within the separator pores is melted, to form a hardened fluoric synthetic resin within the separator base pores to prevent the reformed fuel and air from permeating the separator.