Abstract: A hollow fiber membrane type blood purification device packed with hollow fiber membranes comprising a polysulfone resin and polyvinylpyrrolidone. Even when sterilized by irradiation with a radiation, the hollow fiber membrane type blood purification device is less apt to suffer polyvinylpyrrolidone elution and can be inhibited from decreasing in blood compatibility. The purification device is of the type called semi-dry, and is lightweight and has excellent handleability. The hollow fiber membrane type blood purification device comprises a bundle of hollow fiber membranes comprising a polysulfone resin and polyvinylpyrrolidone, a container packed therewith, and a potting agent disposed between each bundle end and the container to hold the bundle and thereby form a hollow-fiber-membrane inside chamber and a hollow-fiber-membrane outside chamber.