Patent ID: 8455059

Claim:
A method of producing a gas barrier layer made of silicon nitride, silicon carbide or silicon carbonitride by plasma-enhanced CVD, comprising: supplying a material of the gas barrier layer to a film deposition chamber; adjusting the film deposition chamber to a predetermined pressure and traveling an elongated flexible film along a predetermined travel path through the film deposition chamber; starting plasma discharge for forming the gas barrier layer in the film deposition chamber; and producing the gas barrier layer by using a plasma after a first predetermined period of time has elapsed from a start of the plasma discharge on a surface of the elongated flexible film traveling along the predetermined travel path, wherein the elongated flexible film has a film base portion to serve as a product and a guide base portion connected to an advancing end side of the film base portion, the guide base portion not serving as a product, wherein the plasma discharge for forming the gas barrier layer is started before a boundary between the film base portion and the guide base portion reaches the film deposition chamber, and wherein a point in time when a second 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 first predetermined period of time has elapsed from the start of the plasma discharge for forming the gas barrier layer.