A method for manufacturing a top insulator for a secondary battery, which is intended to be inserted into a case of the secondary battery, the method comprising: a step of preparing a top insulator fabric by applying silicone rubber to at least one surface of a glass fiber fabric formed by crossing weft yarns and warp yarns of glass fiber raw yarns; and a step of punching the top insulator fabric, wherein the step of preparing the top insulator fabric comprises a step of applying first silicone rubber, and the step of applying the first silicone rubber comprises: a step of applying a first solution, which is prepared by dissolving a first silicone polymer into the first solution, to the at least one surface; a step of scrapping off the first solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied first solution to apply the first silicone rubber, and wherein the step of preparing the top insulator fabric further comprises a step of applying second silicone rubber, and the step of applying the second silicone rubber comprises, after the step of applying the first silicone rubber,: a step of applying a second solution, which is prepared by dissolving a second silicone polymer into the second solution, to the surface; a step of scrapping off the second solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied second solution to apply the second silicone rubber. a step of preparing a top insulator fabric by applying silicone rubber to at least one surface of a glass fiber fabric formed by crossing weft yarns and warp yarns of glass fiber raw yarns; and a step of punching the top insulator fabric, wherein the step of preparing the top insulator fabric comprises a step of applying first silicone rubber, and the step of applying the first silicone rubber comprises: a step of applying a first solution, which is prepared by dissolving a first silicone polymer into the first solution, to the at least one surface; a step of scrapping off the first solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied first solution to apply the first silicone rubber, and wherein the step of preparing the top insulator fabric further comprises a step of applying second silicone rubber, and the step of applying the second silicone rubber comprises, after the step of applying the first silicone rubber,: a step of applying a second solution, which is prepared by dissolving a second silicone polymer into the second solution, to the surface; a step of scrapping off the second solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied second solution to apply the second silicone rubber. a step of applying a first solution, which is prepared by dissolving a first silicone polymer into the first solution, to the at least one surface; a step of scrapping off the first solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied first solution to apply the first silicone rubber, and wherein the step of preparing the top insulator fabric further comprises a step of applying second silicone rubber, and the step of applying the second silicone rubber comprises, after the step of applying the first silicone rubber,: a step of applying a second solution, which is prepared by dissolving a second silicone polymer into the second solution, to the surface; a step of scrapping off the second solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied second solution to apply the second silicone rubber. a step of applying a second solution, which is prepared by dissolving a second silicone polymer into the second solution, to the surface; a step of scrapping off the second solution remaining on the surface of the glass fiber fabric with a knife; and a step of drying the applied second solution to apply the second silicone rubber.