To chemically remove a film in a condition where an explosion-proof band is still installed, and prevent generation of a pinhole and a pit at reproducing time by removing a multilayer film by soaking it in an alkali hydroxide solution.

In a cathode-ray tube(CRT) 1, in the final stage when an explosion-proof band 7 or the like is installed, a surface of a face panel 2 is coated with a reflection preventive film 6. Next, the film 6 is inspected, and when it is defective, a film 6 process to remove the film 6 is started, and an alkali hydroxide solution 12 is heated and agitated so that a temperature becomes 60°C to 70°C±2°C in a solution tank 10, and is put at a constant temperature. Next, a film 6 part coating panel 2 surface of the CRT is soaked in the solution 12, and the film 6 is soaked for a prescribed preset time, and is dissolved and removed. Therefore, removing work of the film 6 is easily automated, and since the film 6 is chemically dissolved, a pit defective is wholly eliminated, and a fraction defective at reproducing time can be reduced to 5% or less to conventional 20% to 30%.