The present invention relates to a method for manufacturing a barrier film comprising highly refined cellulose, said method comprising: a) providing a highly refined cellulose pulp suspension comprising highly refined cellulose pulp having a Schopper-Riegler (SR) number in the range of 40-98 as determined by standard ISO 5267-1 and a content of fibers having a length >0.2 mm of at least 7 million fibers per gram based on dry weight, at a consistency in the range of 0.1-1.5 wt %; b) forming a web of the highly refined cellulose pulp suspension and dewatering the web in a paper machine former on a wire to a consistency of at least 5 wt % to obtain a substrate web, wherein the white water removed from the pulp contains 2-25 wt %, preferably 5-20 wt % and more preferably at least 5-15 wt % of the solids of the highly refined cellulose pulp suspension provided in step a); c) optionally further dewatering and optionally drying the substrate web; d) coating the optionally further dewatered and optionally dried substrate web with a coating suspension comprising cellulose fines or microfibrillated cellulose to obtain a coated web; and e) dewatering and/or drying the coated web to obtain a barrier film comprising highly refined cellulose.