NOVELTY - A propylene-based resin micropore film is manufactured by preparing propylene-based resin film by supplying propylene-based resin to extruder, melt-kneading, and extruding from T-die attached at front-end of extruder, curing at temperature of less than or equal to 60 degrees C higher than melting point of propylene-based resin, curing at temperature of less than or equal to 10 degrees C lower than melting point of propylene-based resin film, and performing 1st stretching of propylene-based resin film 1.1-1.8 times to direction of extrusion at - 20-40 degrees C at temperature in which surface temperature is less than or equal to 60 degrees C higher than melting point of resin.    USE - Manufacture of propylene-based resin micropore film for lithium ion battery.    ADVANTAGE - Micro hole of uniform size is formed in propylene-based resin micropore film uniformly, propylene-based resin micropore film has entirely excellent air permeability, passage of lithium ion is smooth and uniform when using the film for a lithium ion battery, and lithium ion battery can prevent occurrence of dendrite short and has excellent and stable battery performance over a long period of time.    DETAILED DESCRIPTION - A propylene-based resin micropore film is manufactured by preparing propylene-based resin film by supplying propylene-based resin to extruder, melt-kneading, and extruding from T-die attached at front-end of extruder, curing at temperature of less than or equal to 60 degrees C higher than melting point of propylene-based resin, curing at temperature of less than or equal to 10 degrees C lower than melting point of propylene-based resin film, performing 1st stretching process of propylene-based resin film 1.1-1.8 times to direction of extrusion at - 20-40 degrees C at temperature in which the surface temperature is less than or equal to 60 degrees C higher than melting point of propylene-based resin, performing 2nd stretching process simultaneously biaxially in width direction 1.6-3 times to direction of extrusion at temperature less than or equal to 10 degrees C lower than melting point of propylene-based resin and stretching angle ( alpha ) of less than or equal to 2 degrees , and annealing propylene-based resin film. An INDEPENDENT CLAIM is included for propylene-based resin micropore film which has a micro hole penetrating in the front and back in which variation coefficient of the hole longitudinal diameter in the opening end of the micro hole is less than or equal to 40%.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the deformed state of the amorphous part of a propylene-based resin film.    Amorphous part (C)