TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The gas barrier layer is formed on the surface of flexible film. The flexible film is elongated and the gas barrier layer is formed on the surface of the flexible film which is in longitudinal direction. A marking which can be visually confirmed is marked at a specified portion of at least one of the flexible film or gas barrier layer after predetermined period of time has elapsed from the initial stage of the plasma discharge. The elongated flexible film has a film base portion to be served as a product and a guide base portion connected to an advancing end side of the film base portion, where the guide base portion is not served as a product. The plasma discharge for forming the gas barrier layer is started before a boundary between film base portion and guide base portion reaches the film deposition chamber. A point in time when another predetermined period of time elapsed from entry of the boundary between the film base portion and the guide base portion into the film deposition chamber is regarded as a point in time when the predetermined period of time has elapsed from the initial stage of the plasma discharge for forming gas barrier layer. The guide base portion is made of a material which is similar to the material of the film base portion. The flexible film comprises a base component and a layer structure formed on the base component including at least one gas barrier layer being formed on the surface of the layer structure comprising another gas barrier layer. The gas barrier layer is formed at 120 degrees C or less. The gas barrier layer is formed at static film deposition rate of 300 nm/minute or more. The predetermined period of time is 3 seconds or more. The method involves starting the plasma discharge with a shutter for preventing formation of gas barrier layer on the flexible film closed and opening the shutter after the predetermined period of time has elapsed from the initial stage of the plasma discharge to form gas barrier layer. The shutter is made of a material which is identical to material of flexible film, preferably dielectric material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: At least a portion of the surface of the flexible film is formed with an organic material.