PROBLEM TO BE SOLVED: To provide a leucocyte removal filter improving filtration performances by leaving no air in a housing.SOLUTION: A leucocyte removal filter 10A for removing leucocyte from blood, includes: a housing 100A including an inflow port 110 in which the blood inflows, an outflow port 120 from which the blood outflows, and an exhaust port 130A capable of exhausting an air； and a filtration film 200 that is disposed in the housing 100A so as to separate the housing 100A into the inflow port 110 side and the outflow port 120 side and the exhaust port 130A side, and that removes the leucocyte in the blood. In a use state, the outflow port 120 is provided on a lower side of the housing 100A, the exhaust port 130A is provided on the upper side of the housing 100A, and a cross-sectional area of the inflow port 110 is larger than the cross-sectional area of the outflow port 120.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】筐体内に空気を残留させないことで濾過性能を向上させた白血球除去フィルタを提供すること。【解決手段】血液中から白血球を除去するための白血球除去フィルタ１０Ａであって、血液が流入する流入ポート１１０と、血液が流出する流出ポート１２０と、空気を排出可能な排出ポート１３０Ａと、を有する筐体１００Ａと、前記筐体１００Ａ内に、前記筐体１００Ａを前記流入ポート１１０側と前記流出ポート１２０及び前記排出ポート１３０Ａ側とに隔てるように配置され血液中の白血球を除去する濾過膜２００と、を備え、使用状態において、前記流出ポート１２０は前記筐体１００Ａの下部に設けられ、前記排出ポート１３０Ａは前記筐体１００Ａの上部に設けられ、前記流入ポート１１０の断面積は、前記流出ポート１２０の断面積よりも大きい。【選択図】図１
