A guide device is provided for guiding a workpiece into or out of a processing machine. The processing machine can have a conveying means for conveying the workpiece in a feed direction (D). Further, the processing machine can have a support surface with air outlets that are adapted to create an air cushion between the support surface and the workpiece using exiting air. The support surface can be arranged at a machine infeed or a machine outfeed of the processing machine and have an extension portion, which can be arranged adjacent to a conveying means end portion of the conveying means along the feed direction (D).