Abstract: An apparatus for cryoprecipitation of blood plasma, where the blood from a patient is fed to a plasma separator (1) in order to obtain blood plasma which is then cooled to about +4 degrees centigrade. The blood plasma from the plasma separator is next fed into a container (5). As the contents of the container are kept at a sufficiently low temperature, cryoprecipitation occurs in the container. The blood plasma from the container is then circulated preferably in a loop past a plasma filter (60), where a cooling unit (9) is placed on a branch of the loop (7,8). The filtrate from the plasma filter (6) is finally returned to the patient after it has been warmed in a heating unit (11).