Disclosed is a hollow fiber membrane module including a case and a hollow fiber membrane built in the case, wherein the hollow fiber membrane contains a polysulfone-based polymer and a hydrophilic polymer, and satisfies the following (A) and (B), and an amount of an eluted substance contained in a liquid obtained by circulating ultrapure water heated at 37°C through a passage of an inner surface side of the hollow fiber membrane for 4 hours at 200 mL/min is 1.0 mg/m2 or less:(A) an insoluble component accounts for less than 3% by mass of the total mass of the hollow fiber membrane when the hollow fiber membrane is dissolved in N,N-dimethylacetamide and(B) a flexible layer exists on a surface of a functional layer in a wet state and the flexible layer has a thickness of 7 nm or more. The present invention provides a hollow fiber membrane module including a hollow fiber membrane containing a polysulfone-based polymer and a hydrophilic polymer built therein, which elutes little eluted substance and exhibits high biocompatibility, while change in performance due to crosslinking of the hydrophilic polymer is suppressed.
