Abstract: A separation membrane for blood processing, wherein the separation membrane for blood processing includes: a separation membrane containing polysulfone-based polymer and polyvinylpyrrolidone; and a coating film provided on at least a part of the surface of the separation membrane and containing a polymer material having a structure represented by the following general formula (1): wherein R1 is a hydrogen atom or a methyl group; R2 is a methyl group or an ethyl group; n is 2 to 6 and m is 1 to 3; P denotes the number of repetition; and a plurality of each of R1, R2, n, and m present in one molecule may be the same or different.