The present disclosure concerns a hemodialyzer for the purification of blood and use thereof. The hemodialyzer comprises a bundle of hollow fiber membranes, wherein the hollow fiber membranes have an inner diameter (dB) within the range of 168-175 μm, a fiber wall thickness (δm) within the range of 25-26 μm, and an effective length (L) within the hemodialyzer within the range of 207-287 mm. The bundle of hollow fiber membranes has a packing density within the range of 57.5-60.0%, and a total membrane surface area (Atot) within the range of from 1.64 to 1.73 m2.