Provided is a separator for a fuel cell that can suppress a decrease in the power generation performance of the fuel cell by reducing the contact resistance of the separator. Specifically, provided is a separator for a fuel cell, the separator being adapted to be in contact with a MEGA (power generation portion) including a membrane electrode assembly of the fuel cell so as to separate the MEGA from a MEGA of an adjacent fuel cell, the separator including a metal substrate made of metal; and a tin oxide film covering a surface of the metal substrate on the side of the MEGA. The tin oxide film is made of tin oxide containing 1 to 10 atom % of aluminum.