Abstract: A filter sheet media (1) for air/gas filtering applications fulfilling the criteria of standard EN779:2012 class M6 filter media, the filter sheet media (1) comprises: a first group of glass fibers (20) having a fiber diameter in a range of greater or equal to 6 ?m up to 20 ?m; a second group of glass fibers (30) having a fiber diameter in a range of 0.2 ?m to less than 6 ?m; a binder (40); the second group of glass fibers (30) have a fiber distribution gradient over the thickness (13) of the filter sheet media (1) so that the second group of glass fibers (30) are distributed through the thickness (13) of the filter sheet media (1), the filter sheet media (1) having more second group of glass fibers (30) near the first surface (11) than the second surface (12). Also disclosed is a method for manufacturing.