A method of contactlessly advancing a substrate (140), comprising: —providing a process tunnel (102), extending in a longitudinal direction and bounded by at least a first (120) and a second (134) wall; —providing first and second gas bearings (124, 134) by providing substantially laterally flowing gas alongside the first and second walls respectively; —bringing about a first longitudinal division of the process tunnel into a plurality of pressure segments (116), wherein the gas bearings (124, 34) in a pressure segment have an average gas pressure that is different from an average gas pressure of the gas bearings in an adjacent pressure segment; —providing a substrate (140) in between the first wall (120) and the second wall (130); and 1—allowing differences in average gas pressure between adjacent pressure segments (116) to drive the substrate along the longitudinal direction of the process tunnel.