The invention relates to a device for transporting a flat substrate through a coating plant consisting, for example of a plurality of different sputtering cathodes to which flat substrates, for example glass plates, are successively transported in vacuum. The aim of said invention is to avoid abrasion between said glass plates and a support. For this purpose, a glass plate is distanced from the support by a compressed gas coming through relatively few-numbered and small-sized orifices arranged in a gas channel. As far as small sizes of said orifices prevent any rapid pressure compensation between the gas channel and the rest of said coating plant when it is at atmospheric pressure on in vacuum, said gas channel is separated from the rest of the plant and provided with an individual gas pipe which makes it possible to introduce into the gas channel or pumped out therefrom.