Abstract: This invention relates to a device for drying, by micro-waves, the selvedge of an advancing flat material, particularly textile material, wherein it comprises a preferably rectangular waveguide of which one end terminates in a short circuit and the other by a bend for connection to the generator. The outer part of the bend, the contiguous face of the guide and the short circuit are provided with a single slot made along the median plane, through which is introduced the selvedge of the material inside the guide. The face of the guide opposite the slot comprises orifices connected via a chamber to a source of suction. Two lips, parallel to each other and to the median plane extend on either side of an all along the slot; their ends form a slight flare. These lips form a quarter-wave trap and facilitate introduction of the selvedge into the guide.