A separator of a fuel cell includes a base material and a surface treatment layer formed on the base material. The surface treatment layer includes a base material-side portion made from metal and a base material opposite-side portion made from carbon formed at an atom level or composite materials of carbon and metal or semi-metal. The surface treatment layer may further include carbon particle composite layer formed on the base material opposite-side portion formed at an atom level. In a manufacturing method of the above separator of a fuel cell, the base material opposite-side portion is formed by dry coating.