An object of the present invention is to provide a hollow-fiber membrane blood purification device having an improved antioxidant performance, good water permeation performance and blood compatibility performance, and economic rationality. The present invention provides a hollow-fiber membrane blood purification device including hollow-fiber membranes filled in a vessel, in which the hollow-fiber membranes contain a hydrophobic polymer, a hydrophilic polymer and a fat-soluble vitamin, when a hollow-fiber membrane bundle is divided into five sections in a lengthwise direction and divided sections positioned in endmost portions are defined as body end portions, an amount of the fat-soluble vitamin present in at least one of the body end portions is the largest among amounts of the fat-soluble vitamin present respectively in all the divided sections, and an amount of the fat-soluble vitamin per m 2 of a hollow-fiber membrane inner surface of the at least one body end portion is 20 mg/m 2 or more and 300 mg/m 2 or less.