MICROPOROUS MEMBRANE AND MANUFACTURING METHOD THEREFOR

The present invention relates to a porous membrane including cellulose fibers, wherein the surface area determined by congo red coloring of the re-dispersed cellulose fibers after the cellulose fibers of the porous membrane are re-dispersed in accordance with the re-dispersion method for normal paper specimens according to JIS P 8120 is from 100 to 300 m/g. The porous membrane according to the present invention can provide a separator for electrochemical devices with superior properties, at a reasonable cost.