Nonwoven material of two or more layers, in particular with long-term filter properties and manufacture thereof

A multilayered filter material comprising nonwovens made of polymer fibers or filaments, said filter material including a depth filter for filtering out particles throughout its entire depth and a fine filter for filtering out particles along its surface, both filters having a homogeneous density perpendicular to their surface and being joined together by adhesive or welding in such a way that the area so joined does not exceed 75%, the fine and depth filters each comprising a filament nonwoven with the depth filter having a thickness from 2 to 20 times greater than the fine filter, the depth filter having a basis weight from 150 to 500 g/m.sup.2 and the fine filter having a basis weight from 30 to 100 g/m.sup.2, and wherein the fiber denier of the depth filter is between 4 and 20 dtex and the fiber denier of the fine filter is between 1 and 6 dtex whereby the linear densities of the fine filter are smaller than the linear densities of the depth filter.