Filtering device consists of a bundle of curled hollow fibers arranged in a cylindrical filter housing. The fibers have a sinusoidal texture and are curled corresponding to the following equation: 5.d lambda L/12.1/(1 + 2D/L) (where lambda = the wavelength of the curled hollow fibers; d = the outer diameter of the hollow fibers; L = the effective length of the hollow fibers; and D = the diameter of the fiber bundle). Preferred Features: The amplitude a of the sinusoidal curl is formed by the following equation: d/5 a lambda /5.