<;P>;PROBLEM TO BE SOLVED: To provide a hollow fiber membrane having excellent &beta;2-MG removing performance while suppressing albumin leakage as much as possible in the hollow fiber membrane having a uniform membrane structure and a blood purifier incorporating the same. <;P>;SOLUTION: The hollow fiber membrane has the uniform membrane structure, and the blood purifier has a liquid holding ratio of 170% or more, albumin sieving coefficient of 5% or less, and the excellent &beta;2-microglobulin removing performance. <;P>;COPYRIGHT: (C)2009,JPO&INPIT