[Problem] To provide a blood treatment instrument, in which a blood treatment member can secure an effective filtration area substantially two times greater than those of conventional ones and therefore it becomes possible to largely reduce the filtration time.[Solution] A first blood treatment member 5U formed by stacking multiple non-woven fabrics each having a predetermined thickness and a second blood treatment member 5D formed by stacking multiple non-woven fabrics each having a predetermined thickness are arranged in a first housing 2/U and a second housing 2/D, respectively. The first blood treatment member 5U and the second blood treatment member 5D are arranged in such a manner that inside filtration sections 5FI/U and 5FI/D face each other. A first blood chamber 2.I is formed between the inside filtration sections 5FI/U and 5FI/D, and a second blood chamber 2.2 is formed between the inner periphery of the first housing 2/U and an outside filtration section 5FO/U of the first blood treatment member 5/U and between the inner periphery of the second housing 2/D and an outside filtration section 5FO/D of the second blood treatment member 5D. A blood inlet port 7I is formed so as to be communicated with the first blood chamber 2.1 (a blood inflow chamber 2IR), and a blood discharge port 7O is formed so as to be communicated with the second blood chamber 2.2 (a blood outflow chambers 20R/U and 20R/D).[Problème] Le problème décrit par la présente invention est de fournir un instrument de traitement du sang, dans lequel un élément de traitement du sang peut assurer une zone de filtration efficace sensiblement deux fois plus grande que celles des appareils classiques, ce qui permet la possibilité de réduire considérablement le temps de filtration. [Solution] Un premier élément 5U de traitement du sang+9t est formé par lempilage de multiples tissus non tissés ayant chacun une épaisseur prédéterminée et un second élément 5D de traitement du sang est formé par lempila
