Electric double layer capacitor (EDLC) is an energy device which stores electrical charge in the electric double layer caused between polarizable electrode and interfacial surface of electrolyte solution. We used various carbon materials including ones with large specific surface area and rich meso pores as electrodes for EDLC. We have investigated the influence of pore structures of the carbon materials on the EDLC performance. We calculated specific surface area, micro pore volume and meso pore volume from the isothermal equilibrium curve of nitrogen adsorption by using the B.E.T method. We calculated the pore volume distribution from the Dollimore-Heal method. We calculated the electric double layer capacitance based on the constant current density method. The cell constructed is bipolar system and the electrolyte solution is 1 mol/l H₂SO₄. We found that the relation between the electric double layer capacitance and the specific surface area is not a linear relation but a plateau relation. And also, we found that in the region of low current density the micro pore volume is the important property for electric double layer capacitance while in the region of high current density the meso pore volume is the important property for it.