In order to provide a separator for a fuel cell which is improved in cell characteristics by controlling a wetting property of the separator for a fuel cell and a production process for the same, assumed is a constitution in which in a separator A for a fuel cell molded from at least from a carbon material, a hydrophilic functional group is formed and increased on a surface part of a flow passage surface 11 in the separator 10 by irradiation treatment of a YAG laser apparatus 20 and in which an uneven part having an average surface roughness Ra of less than 50 .mu.m is formed.