Disclosed herein is a roll-to-roll long base material surface processing device capable of performing surface processing on a long base material with little occurrence of wrinkling in the long base material at low costs. The surface processing device includes: two can rolls that cool a long resin film transferred in a roll-to-roll manner in a vacuum chamber with a cooling medium circulated therein by wrapping the long resin film around outer circumferences thereof; and surface processing units typified by magnetron sputtering cathodes provided so as to face the outer circumferences of the two can rolls, wherein a second can roll of the two can rolls other than a most upstream first can roll has a gas release mechanism that releases a gas from the outer circumference.