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.