A plate-shaped filter insert for, in particular, a gas filter with a seal which projects outward on a first of two opposite plate surfaces should be simple and inexpensive to produce with good durability. For this purpose, such a filter insert has the following features: - the filter material (1) is designed as a web material folded in a zigzag shape, each of whose folds on the top side are sealed by a first sealant strip (2), - the first sealant strips (2) each project bent outward at one of the two opposite upper plate sides formed by the backs of the folds, - at the end folds lying in longitudinal direction of the web material, a second sealant strip (3) running transverse to this longitudinal direction is attached, - the second sealant strips (3) are each bonded tightly to the first sealant strips (2), - a circumferential sealant material (4) is applied to the first and second sealant strips (2, 3) bonded tightly to one another.