HOLLOW FIBER MEMBRANE MODULE

A hollow fiber membrane module that increases a ratio of a membrane area contributing to membrane separation effect. On an inner wall surface of a case , at least one flow-straightening projection and at least one flow-disturbing projection are provided. The flow-straightening projection projects toward an outer circumferential surface of a hollow fiber membrane bundle to secure a gap between the inner wall surface of the case and the hollow fiber membrane bundle and extends from one end side toward the other end side of the case and straightens a flow of fluid. The flow-disturbing projection extends along a circumferential direction of the case and disturbs the flow of the fluid.