The present invention relates to a method of manufacturing a porous carbon electrode, the method including: applying a metal film or metal particles to one surface of a carbon electrode; heat treating the carbon electrode to which the metal film or the metal particles are applied; and forming one surface of the carbon electrode in a porous structure by making the metal film or the metal particles penetrate into one surface of the carbon electrode, and the efficiency of the carbon electrode as an electrode may be improved while increasing a surface area of a carbon structure.