Sputtering device and method for producing long film with thin layer

A sputtering device configured to form a thin layer on a long film, the sputtering device comprising:

• a vacuum chamber;
• a vacuum pump for evacuating the vacuum chamber;
• a supply roll for supplying the long film;
• a storage roll for storing the long film;
• a film depositing roll that is provided in the vacuum chamber and conveys the long film along a surface thereof;
• a target facing the film depositing roll;
• a gas pipe for supplying a gas into the vacuum chamber;
• a plurality of guide rolls for guiding the long film;
• a plurality of guide roll shafts provided at each of both ends of the plurality of guide rolls;
• a plurality of bearings for supporting the plurality of guide roll shafts;
• and
• a plurality of insulators configured to insulate the guide roll shafts and the plurality of bearings from each other,
• wherein contact surfaces of the guide rolls with the long film are kept at a floating potential.