Blood filter

A blood filter (1) comprising a bubble separating section (2) including a generally cylindrical chamber (10) for allowing bubbles to separate from blood, an air discharging vent (12) at an upper end of the chamber (10), and an inlet conduit (13) horizontally extending from the chamber (10) for introducing blood into the chamber (10); and a blood filter section (3) disposed below the bubble separating section (2), including an outlet (16) at a lower end for discharging blood and a filter member (1 disposed between the inlet (13) and the outlet (16) is characterized in that the axis of the inlet conduit (13) extends substantially parallel to a tangent to the generally circular chamber (10) at the connection between the chamber (10) and the inlet conduit (13), and an inflow portion (15) is disposed between the inlet conduit (13) and the chamber (10) so as to define a flowpath merging the inlet conduit (13) to the chamber (10), whereby the inflow portion (15) directs incoming blood from the inlet conduit (13) so as to flow as a substantial laminar flow to a swirl flow of blood in the chamber (10) and then merge with the swirl flow. The apparatus has high bubble removal capacity in that few bubbles are conveyed to the filter member (1 since newly introduced blood does not disturb the existing swirl flow of blood in the chamber (10).