PROBLEM TO BE SOLVED: To provide a hollow fiber module suppressing pressure loss for preventing the interruption of treatment accompanying pressure rise during CRRT operation and suppressing the adhesion of blood cell components at a hollow fiber membrane inflow port by suppressing the occurrence of residence when flowing from a header interior space into a hollow fiber membrane.SOLUTION: A hollow fiber module includes: a cylindrical container a bundle of hollow fiber membranes 3 installed within the cylindrical container a potting resin part fixing both end parts of the bundle of the hollow fiber membranes 3 to both end parts of the cylindrical container and headers disposed at both end parts of the cylindrical container respectively. A ratio (Ri/Re) of the inside diameter (Ri) of the hollow fiber membrane 3 to the inside diameter (Re) of the opening end part of the hollow fiber membrane 3 of the entrance side of a fluid is exhibited as Ri/Re<1 and a ratio (Re/Ro) of Re to the outside diameter (Ro) of the hollow fiber membrane 3 is exhibited as 0.5≤Re/Ro<1.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2018,JPO&INPIT【課題】CRRT施行中の圧上昇に伴う治療中断を防ぐべく、圧力損失を抑制するとともに、ヘッダー内部空間から中空糸膜内へ流れ込む際の滞留の発生を抑え中空糸膜流入口における血球成分の付着を抑制する。【解決手段】中空糸モジュールは、筒状容器と、該筒状容器内に装填される中空糸膜3の束と、該中空糸膜3の束の両端部を筒状容器の両端部に固定するポッティング樹脂部と、筒状容器の両端部にそれぞれ設けられるヘッダーと、を備えており、中空糸膜3の内径(Ri)と流体の入口側の該中空糸膜3の開口端部の内径(Re)の比(Ri/Re)が Ri/Re<1であって、 Reと該中空糸膜3の外径(Ro)の比(Re/Ro)が、 0.5≦Re/Ro<1である。【選択図】図4
