<；P>；PROBLEM TO BE SOLVED: To provide a leukocyte removal filter whose leukocyte removal performance is higher compared with a conventional filter and which is manufactured with a simple method without capturing other blood components, i.e, erythrocyte and plasma. <；P>；SOLUTION: The filter includes a filter material which has amino group-modified oligosaccharide containing polyurethane at least on the surface and where an average fiber diameter is 1.0-2.5 &mu；m. The filter material fills a container having a liquid introduction port and a derivation port. The plurality of filter materials are laminated in a flow direction. <；P>；COPYRIGHT: (C)2011,JPO&INPIT
