FIELD: polymer materials. SUBSTANCE: invention may be applied in production of liquid filters, air filters for purifying interior atmosphere in sterile semiconductor-production rooms, and to create favorable conditions for precision devices in medicine, biochemistry, etc. Film is manufactured by stretching non-molten polytetrafluoroethylene in longitudinal direction at 250-320 C and in transverse direction at 100-200 C. Average pore size of thus obtained film is 0.2-0.4 mcm, and pressure fall in water passing the film at flow velocity 5.3 mm/s is 20-50 mm water column. EFFECT: enhanced filtration efficiency. 7 cl, 2 dwg, 3 tbl, 9 ex
