NOVELTY - A reactive ion etching processing apparatus consisting of a metal roll electrode and a ground electrode is used. A gas containing nitrogen, helium and/or argon for oxidation, and vaporized organic silicon compound are introduced between the electrodes. An intermediate contact layer (101) is formed in the surface of base material (100) driven on the metal roll electrode by plasma-enhanced chemical vapor deposition. A gas-barrier layer (102) is formed by dry coating on the surface of intermediate contact layer, to obtain a gas-barrier film.    USE - Manufacture of gas-barrier film (claimed) used for packaging materials of foodstuffs, pharmaceuticals, hard disks, and semiconductor modules, and for protection sheets of solar cells.    ADVANTAGE - The method enables high-speed manufacture of gas-barrier films having excellent adhesiveness with respect to base material and gas-barrier layer even after retort sterilization, boil process, pressure cooker test, and environmental endurance test, with high productivity, occupying little space. In-line processing is possible.    DETAILED DESCRIPTION - A gas-barrier film is obtained by forming an intermediate contact layer and a gas-barrier layer sequentially on a web-like base material. A reactive ion etching processing apparatus consisting of a metal roll electrode, which is a high-frequency application electrode in which a base material is driven, and a ground electrode arranged in a shape where the metal roll electrode follows as a counter electrode in circular arc shape or multifaceted form with a magnet of one or more pairs of south-north pole installed on the surface, is used. The shortest distance between the electrodes is 10-100 mm. A gas containing nitrogen, helium and/or argon for oxidation, and vaporized organic silicon compound are introduced between the electrodes. The pressure in the process space is set to 0.5-20 Pa and high frequency is set to 30 kHz to 4 MHz. A high-density plasma is generated between the electrodes by applying electric power such that the ratio of electric power (kW) supplied to the metal roll electrode and area (m2) of plasma exposure is 4 kW/m2 or more. The intermediate contact layer having a thickness of 3 nm or more is formed in the base-material surface driven on the metal roll electrode by plasma-enhanced chemical vapor deposition. The gas-barrier layer is formed by dry coating on the surface of intermediate contact layer.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the gas-barrier film.    Base material (100)    Intermediate contact layer (101)    Gas barrier layer (102)