A method of manufacturing a double-sided polarizing plate, comprising: attaching transparent films to both surfaces of a polarizer via adhesive layers; irradiating the adhesive layers with active energy rays in an amount of light of 200mJ/cm 2 or more through an energy source located in a single direction, based on the polarizer; and thermally treating a surface of the transparent film facing away from the energy source using a drum at a temperature of 10°C to 25°C, wherein the irradiating of the active energy rays and the thermally treating at 10°C to 25°C are performed simultaneously with each other, wherein the method further comprises forming a primer layer between at least one surface of the adhesive layer and at least one surface of the transparent film, wherein the primer layer is formed using a primer composition containing 1 to 50 parts by weight of a urethane polymer, 0.1 to 10 parts by weight of water-dispersible fine particles, and the balance of water, based on a total of 100 parts by weight of the primer composition, wherein the primer layer has a thickness of from 100 nm to 1 μm, and wherein peel strength of the adhesive layer formed on the transparent film at which the energy source is located is equal to or greater than 3N at a peel angle of 90°, the adhesive layers are formed using a cationic adhesive, the cationic adhesive comprises: based on a total of 100 parts by weight of an adhesive composition, 5 to 90 parts by weight of an epoxy compound having at least two epoxy groups in a molecule; 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; and 0.5 to 20 parts by weight of an optical cationic photopolymerization initiator; the epoxy compound is a combination of a first epoxy compound containing one or more epoxidized alicyclic groups and a second epoxy compound containing one or more glycidyl ether groups; and the first epoxy compound and the second epoxy compound are mixed at a weight ratio of 1:1 to 3:1. attaching transparent films to both surfaces of a polarizer via adhesive layers; irradiating the adhesive layers with active energy rays in an amount of light of 200mJ/cm 2 or more through an energy source located in a single direction, based on the polarizer; and thermally treating a surface of the transparent film facing away from the energy source using a drum at a temperature of 10°C to 25°C, wherein the irradiating of the active energy rays and the thermally treating at 10°C to 25°C are performed simultaneously with each other, wherein the method further comprises forming a primer layer between at least one surface of the adhesive layer and at least one surface of the transparent film, wherein the primer layer is formed using a primer composition containing 1 to 50 parts by weight of a urethane polymer, 0.1 to 10 parts by weight of water-dispersible fine particles, and the balance of water, based on a total of 100 parts by weight of the primer composition, wherein the primer layer has a thickness of from 100 nm to 1 μm, and wherein peel strength of the adhesive layer formed on the transparent film at which the energy source is located is equal to or greater than 3N at a peel angle of 90°, the adhesive layers are formed using a cationic adhesive, the cationic adhesive comprises: based on a total of 100 parts by weight of an adhesive composition, 5 to 90 parts by weight of an epoxy compound having at least two epoxy groups in a molecule; 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; and 0.5 to 20 parts by weight of an optical cationic photopolymerization initiator; the epoxy compound is a combination of a first epoxy compound containing one or more epoxidized alicyclic groups and a second epoxy compound containing one or more glycidyl ether groups; and the first epoxy compound and the second epoxy compound are mixed at a weight ratio of 1:1 to 3:1. based on a total of 100 parts by weight of an adhesive composition, 5 to 90 parts by weight of an epoxy compound having at least two epoxy groups in a molecule; 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; and 0.5 to 20 parts by weight of an optical cationic photopolymerization initiator; 5 to 90 parts by weight of an epoxy compound having at least two epoxy groups in a molecule; 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; and 0.5 to 20 parts by weight of an optical cationic photopolymerization initiator; the epoxy compound is a combination of a first epoxy compound containing one or more epoxidized alicyclic groups and a second epoxy compound containing one or more glycidyl ether groups; and the first epoxy compound and the second epoxy compound are mixed at a weight ratio of 1:1 to 3:1.