Proton Exchange Membrane Fuel Cell (PEMFC) is a device that produces electricity by the electrochemical reaction of hydrogen gas (H2) and oxygen (O2). Themost expensive component in any unit of the fuel cell is a separator it is called Bipolar Plates, it takes 42 % of stack cost. So it takes effort to lower production cost by replacing the fuel cell materials with local raw materials. The main characteristics of the fuel cell separator that is both high conductivity and low porosity. In this research, the manufacture of carbon-based separator with a mixture of polystyrene with a variable ratio of graphite (G), carbon (C) and polystyrene (PS), as well as variations in pressure. Further characterization of the density, porosity, electrical conductivity, hardness, tensile strength, and morphology. The density of the resulting separator meets the requirements for commercial separator is not more than 5 g/cc. Electrical conductivity reaches 105.5705 S/cm on a combination of 90%G/K and 10%PS. Conductive polymer, polyaniline (PANI), was added to increase the electrical conductivity. Due to this addition, the electrical conductivity increased from 105.5705 separator S/cm to 121.9433 S/cm at a ratio of 90 %G/K and 10 %PS/ PANI. While the commercial bipolar plates require 100 S/cm electrical conductivity.