PROBLEM TO BE SOLVED: To provide a production method of a separation membrane with superior blood compatibility, causing little adhesion of protein or organic matter.SOLUTION: In this production method, the separation membrane is wetted with a copolymerized high polymer aqueous solution having both hydrophilic and hydrophobic properties in molecules, and is irradiated while the liquid ratio of the membrane is 20-600%.COPYRIGHT: (C)2006,JPO&NCIPI【課題】血液適合性に優れ、タンパク質や有機物の付着が少ない分離膜の製造方法を提供することにある。【解決手段】分離膜を、分子内に親水性と疎水性を併せ持つような共重合体高分子水溶液で湿潤させ、20~600%の抱液率の状態で放射線照射させることを特徴とする。【選択図】図1