A filter bag includes a first filter material layer including an inflow opening, a second filter material layer having edges along which the second filter layer is joined to the first filter material layer to form an inside space; and a flat, multi-layer filter insert arranged in the inside space and having sections connected, respectively, to the first and second material layers. The filter insert has at least two outer layers defining an intermediate area there between. The intermediate area includes a center layer or an intermediate space for dust collection.