A fuel filter has a filter housing and a fuel filter insert exchangeably arranged in the filter housing and provided with a prefilter element and a main filter element. Prefilter element and main filter element are positioned one behind the other in the filter housing in axial direction of the filter housing. A fuel discharge channel is arranged in the filter housing below the fuel filter insert. In operating position of the fuel filter insert in the filter housing, the raw sides of prefilter element and of main filter element are sealed relative to the fuel discharge channel by seal-tight contact of the fuel filter insert on the filter housing. The raw side of the main filter element, when the fuel filter insert is moved by axial movement away from the operating position, is fluidically connected with the fuel discharge channel via the raw side of the prefilter element.