TECHNOLOGY FOCUS - POLYMERS - Preferred Method: A pattern transfer film is formed on the substrate for pattern formation. Subsequently, the film containing the pattern forming material is formed on the transfer film and annealed. The thermal decomposable polymer is removed from the formed microphase separation structure. The pattern transfer film is etched by setting the other polymer phase as a mask and the pattern of micro phase separation structure is transferred to the pattern transfer film. Subsequently, the substrate is etched by setting the pattern transfer film as a mask and the pattern is transferred to the substrate. EXAMPLE - Styrene and methyl methacrylate monomers were reacted and subjected to vacuum distillation. The product was refluxed with metallic sodium and polymerized using sec-butyl lithium (polymerization initiator). The reaction mixture was cooled to 78degreesC and again reacted with additional amount of styrene monomer of 30 minutes and extracted. Subsequently, suitable amounts of 1,1'-diphenyl ethylene and methyl methacrylate monomer were added, reacted and extracted. The reaction liquid was precipitated and filtered to obtain diblock copolymer of polystyrene-polymethyl methacrylate with molecular weight distribution of 1.04. The diblock copolymer (in wt.%) (2) was dissolved in propylene-glycol monomethyl ether acetate and filtered. The solution was coated on silicon substrate. The substrate was heated at 110degreesC for 90 seconds to vaporize the solvent and annealed in nitrogen atmosphere at 210degreesC for 10 hours and at 135degreesC for 10 minutes to form microphase-separation film. The film was subjected to reactive ion etching process and the polymethyl methacrylate polymer phase was selectively etched. The substrate was exposed by setting the pattern of polystyrene polymer phase as mask and subjected to ashing to remove organic material containing polystyrene, and to form hole of diameter of 12 nm and depth of 15 nm of equal spacing at the surface of the substrate. An electrochemical cell using the obtained porous material in electrode had excellent electric power generation efficiency.