Abstract: A process and apparatus is provided for producing a filter insert for a fluid filter. The insert is comprised of filter material having a number of fold walls arranged in a zigzag-shaped continuous fold. Adjacent fold walls are connected to one another and rest on one another at least in part by means of an adhesive spacer. A strip of the filter material is provided with indentations which determine positions of fold edges. The adhesive spacers are applied to at least corresponding areas of those parts of the strip of filter material which will become adjacent fold walls when the filter insert is complete. The strip of filter material is folded at the indentations in partial steps, including a first partial step of folding the filter material into folds at a small spacing, and a second partial step of pulling the folds apart again by a predetermined amount so that at least some of the adhesive spacers have a height which is not constant in a direction at right angles to the fold edges.