MEDICAL HEAT EXCHANGER, MANUFACTURING METHOD THEREOF AND ARTIFICIAL LUNG DEVICE

A bundle (2) of thin tubes which includes thin heat transfer tubes (1) is sealed by seal members (3a-3c) to form a blood flow path (5) which intersects the thin heat transfer tubes. Headers (6, 7) for the thin heat transfer tubes comprise flow chambers for containing the ends of the bundle of thin tubes, and the headers (6, 7) have introducing and discharging ports (6a, 7a) for a heat medium liquid. The bundle of thin tubes is divided in the direction of the blood flow path to form a layered structure of thin-tube bundle units (12a-12c). The flow chambers are partitioned into divided flow chambers (13a, 13b, 14a, 14b) by partition walls (6b, 7b) to form a flow path via which the heat medium liquid is caused to sequentially pass through each thin-tube bundle unit. One thin-tube bundle unit of the thin-tube bundle units on both sides of the boundary which corresponds to each of the partition walls has an end which protrudes further toward the outside than the end of the other thin-tube bundle unit, and a side surface of the partition wall is in contact with a side surface of the protruded portion of said end. The configuration increases the flow speed of the heat medium liquid which flows in the thin heat transfer tubes, and this enhances the efficiency of heat exchange with an increase in the volume of the blood flow path minimized.