Disclosed is a fuel filter in which is disposed in a fuel suction port of a fuel tank or in a fuel line and used to filter the fuel. At least one of filter materials constituting the fuel filter is made into a multifunctional filter material having a function of trapping dust of different particle diameters in stages, by differing the diameter of the pores in the filter material from the primary side to the secondary side of the filter material so that the size of the pores decreases toward the secondary side.