A transfer-membrane retaining jig (2) that retains a transfer membrane (1) in a separation-transfer device (100) includes: a fixing part (20, 21) that fixes at least one end in a movement direction of the transfer membrane (1), in which the fixing part (20, 21) includes an elastic body (20a, 21a) that abuts the transfer membrane (1) from an opposite side to a dispensing part (50a), and a pressing member (20b, 21b) that presses the transfer membrane (1) against the elastic body (20a, 21a).