The invention relates to a method and device for folding a cover material (4) on a medical sensor (1) that has a carrier material (12) which is to be affixed to the skin of the patient and which is furnished with an adhesion or adhesive layer (3) on the side facing the patient, to which adhesive layer the cover material (4) is applied, wherein a portion of the cover material that is opposite the portion of the carrier material free of the adhesion layer forms a tab (10). The method according to the invention and the device according to the invention are based on using a tool (20) for folding the cover material, said tool having at least two contact surfaces (22, 23) which intersect in an edge (24) running parallel to the plane of the composite of carrier material (12) and cover material (4). The tool (20) is moved along an axis (21) running at an angle to the plane of the composite of carrier material (12) and cover material (4) in such a manner that the tab (10) is seized by the tool (20) and bent over with the tool. After the tab (10) has been folded, pressure is applied to the bent-over section of the carrier material (12) in order to produce a fold edge (8).
