(a) An air ejection nozzle which is provided against a passing plane of a resin film carrying one direction with a clearance and used for ejecting air toward a surface of the resin film, wherein (b) the air ejection nozzle comprises a nozzle housing, and the nozzle housing has an air supply passage therein, an air ejection face facing the passing plane of the resin film, and many air ejection holes opening to the air supply passage and opening in the air ejection face respectively, (c) a figure of each of openings of the many air ejection holes in the air ejection face is circle, (d) the many air ejection holes are arranged in the air ejection face in two rows of a first row and a second row in the direction perpendicular to the carrying direction of the resin film, and a state of arrangement between the air ejection holes of the first row and the air ejection holes of the second row is a zigzag arrangement, and (e) the distance L (mm) between the air ejection face and the passing plane of the resin film, the diameter D (mm) of the respective air ejection holes in the air ejection face, the interval Px (mm) in the carrying direction of the resin film between a first air ejection holes-aligned straight line passing through the centers of the multiple air ejection holes arranged in the first row and a second air ejection holes-aligned straight line passing through the centers of the multiple air ejection holes arranged in the second row, and each interval Py (mm) between the centers of the respectively adjacent air ejection holes in the first air ejection holes-aligned straight line and between the centers of the respectively adjacent air ejection holes in the second air ejection holes-aligned straight line is characterised by the following formulae and: 6 ≤ L / D / Px / Py ≤ 9 4 ≤ L / D ≤ 8 (a) An air ejection nozzle which is provided against a passing plane of a resin film carrying one direction with a clearance and used for ejecting air toward a surface of the resin film, wherein (b) the air ejection nozzle comprises a nozzle housing, and the nozzle housing has an air supply passage therein, an air ejection face facing the passing plane of the resin film, and many air ejection holes opening to the air supply passage and opening in the air ejection face respectively, (c) a figure of each of openings of the many air ejection holes in the air ejection face is circle, (d) the many air ejection holes are arranged in the air ejection face in two rows of a first row and a second row in the direction perpendicular to the carrying direction of the resin film, and a state of arrangement between the air ejection holes of the first row and the air ejection holes of the second row is a zigzag arrangement, and (e) the distance L (mm) between the air ejection face and the passing plane of the resin film, the diameter D (mm) of the respective air ejection holes in the air ejection face, the interval Px (mm) in the carrying direction of the resin film between a first air ejection holes-aligned straight line passing through the centers of the multiple air ejection holes arranged in the first row and a second air ejection holes-aligned straight line passing through the centers of the multiple air ejection holes arranged in the second row, and each interval Py (mm) between the centers of the respectively adjacent air ejection holes in the first air ejection holes-aligned straight line and between the centers of the respectively adjacent air ejection holes in the second air ejection holes-aligned straight line is characterised by the following formulae and: 6 ≤ L / D / Px / Py ≤ 9 4 ≤ L / D ≤ 8