A method for manufacturing a carbon nanostructure-metal composite nanoporous film, comprising: manufacturing a carbon nanostructure-metal composite formed of a round metal particle of 1 to 500nm and a carbon nanostructure by mixing a metal precursor with a dispersion of the carbon nanostructure dispersed in a reducing solvent and heating the resulting mixture; dispersing the carbon nanostructure-metal composite in a solvent by ultrasonic treatment at the presence of a surfactant and coating the carbon nanostructure-metal composite on one surface or both surfaces of a membrane support having micro or nano-sized pores, wherein the surfactant is selected from a non-ionic surfactant, a cationic surfactant, an anionic surfactant and a mixture thereof, and wherein the solvent is selected from the group consisting of water, alcohol, polyols, glycol ethers and a mixture thereof; and fusing the metal on the membrane support by heating the coated membrane support at a temperature of 100 to 700°C, wherein the coating is performed by filtering the carbon nanostructure-metal composite by the membrane support and compressing the carbon nanostructure-metal composite remaining in the membrane support, wherein the carbon nanostructure is selected from the group consisting of a single wall carbon nanotube, a double wall carbon nanotube, a multi wall carbon nanotube, a carbon nano horn, a carbon graphene, a carbon nano fiber or a mixture thereof, and wherein the reducing solvent is selected from the group consisting of polyols, glycol ethers or a mixture thereof; the polyols are selected from the group consisting of glycols, glycerin, threitol, arabitol, glucose, mannitol, galactitol and sorbitol of Formula 1; and the glycol ethers are selected from the group consisting of compounds of Formula 2: [Formula 1] H-(OR 1) n -OH [Formula 2] R 4 -(OR 2) m -OR 3 where R 1 and R 2 are individually selected from the group consisting of linear or branched (C 2 ∼C 10) alkylene; R 3 represents hydrogen, an allyl, (C 1 ∼C 10) alkyl, (C 5 ∼C 20) aryl, or (C 6 ∼C 30) aralkyl group; R 4 is selected from the group consisting of an allyl, (C 1 ∼C 10) alkyl, (C 5 ∼C 20) aryl, (C 6 ∼C 30) aralkyl group, or a (C 2 ∼C 10) alkyl carbonyl group and alkyl of the alkyl carbonyl group may have a double bond at a carbon chain; n and m are individually an integer of 1 to 100. manufacturing a carbon nanostructure-metal composite formed of a round metal particle of 1 to 500nm and a carbon nanostructure by mixing a metal precursor with a dispersion of the carbon nanostructure dispersed in a reducing solvent and heating the resulting mixture; dispersing the carbon nanostructure-metal composite in a solvent by ultrasonic treatment at the presence of a surfactant and coating the carbon nanostructure-metal composite on one surface or both surfaces of a membrane support having micro or nano-sized pores, wherein the surfactant is selected from a non-ionic surfactant, a cationic surfactant, an anionic surfactant and a mixture thereof, and wherein the solvent is selected from the group consisting of water, alcohol, polyols, glycol ethers and a mixture thereof; and fusing the metal on the membrane support by heating the coated membrane support at a temperature of 100 to 700°C, wherein the coating is performed by filtering the carbon nanostructure-metal composite by the membrane support and compressing the carbon nanostructure-metal composite remaining in the membrane support, wherein the carbon nanostructure is selected from the group consisting of a single wall carbon nanotube, a double wall carbon nanotube, a multi wall carbon nanotube, a carbon nano horn, a carbon graphene, a carbon nano fiber or a mixture thereof, and wherein the reducing solvent is selected from the group consisting of polyols, glycol ethers or a mixture thereof; the polyols are selected from the group consisting of glycols, glycerin, threitol, arabitol, glucose, mannitol, galactitol and sorbitol of Formula 1; and the glycol ethers are selected from the group consisting of compounds of Formula 2: [Formula 1] H-(OR 1) n -OH [Formula 2] R 4 -(OR 2) m -OR 3 where R 1 and R 2 are individually selected from the group consisting of linear or branched (C 2 ∼C 10) alkylene; R 3 represents hydrogen, an allyl, (C 1 ∼C 10) alkyl, (C 5 ∼C 20) aryl, or (C 6 ∼C 30) aralkyl group; R 4 is selected from the group consisting of an allyl, (C 1 ∼C 10) alkyl, (C 5 ∼C 20) aryl, (C 6 ∼C 30) aralkyl group, or a (C 2 ∼C 10) alkyl carbonyl group and alkyl of the alkyl carbonyl group may have a double bond at a carbon chain; n and m are individually an integer of 1 to 100.