NOVELTY - A pattern forming material contains block copolymer or graft copolymer having polymer chain containing repeating unit (1) and thermal decomposable polymer chain.    USE - For pattern formation and manufacture of porous material for electrodes of electrochemical cell (all claimed), lithium ion secondary cell and fuel cell, magnetic recording media for hard disk, solar cell, optoelectric transducer, light emitting element, display, light modulator, component and accurate filter.    ADVANTAGE - The pattern forming material enables formation of a pattern of favorable nanometer regularity and provides magnetic recording media of high recording density.    DETAILED DESCRIPTION - The pattern forming material contains block copolymer or graft copolymer having polymer chain containing repeating unit of formula (I) and thermal decomposable polymer chain.    R1, R2 = 1-20C (un)substituted alkyl, aryl, aralkyl or alkoxyl group.    INDEPENDENT CLAIMS are included for the following:    (1) formation of pattern, which involves forming a film containing the pattern forming material on a substrate, annealing the film to form microphase-separation structure in the film, heating the film to more than the thermal decomposition temperature to remove the thermal decomposable polymer phase from the structure, etching the substrate by setting the other remaining polymer phase as a mask, and transferring the pattern of microphase-separation structure to the substrate;    (2) manufacture of porous structure, which involves forming a compact containing the pattern forming material, annealing the compact to form microphase-separation structure into the compact, heating the compact more than the thermal decomposition temperature to remove the thermal decomposable polymer phase from the structure, forming porous structure containing the remaining other polymer phase, and filling the hole of porous structure with inorganic material;    (3) electrochemical cell, which has a pair of electrodes, electrode layer provided among the electrodes. A portion of the electrode exhibits 3-dimensional network structure containing porous structure having continuous hole with correlation distance of 2x(3)1/2 or 4 times of rotational radius of cross-section of the micro domain;    (4) manufacture of porous carbon, which involves mixing the precursor of thermosetting resin, surface activate agent, water and oil to obtain micro emulsion containing colloidal particle containing dispersed precursor of thermosetting resin, curing the precursor of thermosetting resin unevenly distributed in the colloidal particle, removing surface active agent, water and oil from the colloidal particle, and baking the obtained porous structure of cured thermosetting resin material; and    (5) porous carbon structure, which has porous honeycomb structure having cylindrical hole of 0.1-100 nm of average pore size.    DESCRIPTION OF DRAWING(S) - The figure shows the micro phase separation structure of block copolymer.