A barrier fabric with a nano-fibrous layer for mechanical retention of organic substances formed by a sandwich structure containing a basic material from unwoven fabric of “spunbond” type with areal weight of 15 to 50 g/m2 to which at least one nano-fibrous layer is arranged, selected from hydrophilic polymer, a hydrophobic polymer, or in the case of double-layer arrangement, a combination of the hydrophilic polymer in one layer and the hydrophobic polymer in the other layer. The nano-fibrous layer is equipped with a protective covering layer, and the individual layers of the sandwich are connected to each other. The nano-fibrous layer has an organic polymer material with areal weight of 0.05 to 0.3 g/m2 and thickness from 90 to 150 nm. The covering layer is selected from an unwoven fabric of “spunbond” type, “meltblown” type, cotton textile and/or a mixture of cotton and polyester.