A method for continuously subjecting an elongated substrate to vacuum film formation, comprising the steps of: a) unrolling and feeding an elongated substrate wound in a roll form from a first roll chamber in a direction from the first roll chamber toward a second roll chamber, using a first surface as a surface for film formation; b) degassing the substrate fed in the direction; c) forming, in a first film formation chamber, a first material film on the first surface of the degassed substrate, wherein the first film formation chamber comprises a first rotary drum and a first cathode electrode, and the first cathode electrode consists of a plurality of electrode elements; d) forming, in a second film formation chamber, a second material film on the first material film formed on the first surface of the substrate, wherein the second film formation chamber comprises a second rotary drum and a second cathode electrode, and the second cathode electrode consists of a plurality of electrode elements; e) taking up, in the second roll chamber, the substrate in a roll form, the substrate having the second material film laminated on the first material film on the first surface of the substrate; f) unrolling and feeding the substrate taken up in the second roll chamber from the first roll chamber in the direction, using a second surface opposite the first surface as a surface for film formation; g) degassing the substrate fed in the direction; h) forming, in the first film formation chamber, the first material film on the second surface of the degassed substrate; i) forming, in the second film formation chamber, the second material film on the first material film formed on the second surface of the substrate; and j) taking up, in the second roll chamber, the substrate in a roll form, the substrate having the second material film laminated on the first material film on each of the first and second surfaces of the substrate; wherein when forming, in the second film formation chamber, the second material film on the substrate fed in the direction, each of the electrode elements of the first cathode electrode in the first film formation chamber is adapted to be movably disposed in opposed relation to the first rotary drum. a) unrolling and feeding an elongated substrate wound in a roll form from a first roll chamber in a direction from the first roll chamber toward a second roll chamber, using a first surface as a surface for film formation; b) degassing the substrate fed in the direction; c) forming, in a first film formation chamber, a first material film on the first surface of the degassed substrate, wherein the first film formation chamber comprises a first rotary drum and a first cathode electrode, and the first cathode electrode consists of a plurality of electrode elements; d) forming, in a second film formation chamber, a second material film on the first material film formed on the first surface of the substrate, wherein the second film formation chamber comprises a second rotary drum and a second cathode electrode, and the second cathode electrode consists of a plurality of electrode elements; e) taking up, in the second roll chamber, the substrate in a roll form, the substrate having the second material film laminated on the first material film on the first surface of the substrate; f) unrolling and feeding the substrate taken up in the second roll chamber from the first roll chamber in the direction, using a second surface opposite the first surface as a surface for film formation; g) degassing the substrate fed in the direction; h) forming, in the first film formation chamber, the first material film on the second surface of the degassed substrate; i) forming, in the second film formation chamber, the second material film on the first material film formed on the second surface of the substrate; and j) taking up, in the second roll chamber, the substrate in a roll form, the substrate having the second material film laminated on the first material film on each of the first and second surfaces of the substrate;