Blood pump

A blood pump comprising:

• a housing (10) that includes a top surface (2) having an inflow port (1) into which blood flows, a bottom surface (3) placed opposite the top surface (2), and a circumferential periphery (5) joined to the top surface (2) and the bottom surface (3) and having an outflow port (4) from which blood is discharged;
• a bearing (20) placed while pointing from the bottom surface (3) toward the top surface (2) of the housing (10);
• an impeller (40) accommodated in the housing (10) and having driven magnets (30) and in a center a through hole for insertion of the bearing (20);
• and
• a drive magnet (50) that is placed outside the housing (10) so as to be magnetically coupled with the driven magnet (30) in a radial direction of the impeller (40) by way of the circumferential periphery (5) and that rotates around the housing (10) along the circumferential periphery (5), wherein
• when faces of the driven magnets (30) and the drive magnet (50) that are opposite to each other are taken as opposed faces and when faces on the other side of the opposed faces are taken as non-opposed faces, a magnetic substance (60) is placed on the non-opposed face of the drive magnet (50) and a magnetic substance (61) is placed on the non-opposed faces of the driven magnets (30);
• and
• the impeller (40) rotates without contacting the housing (10) and the bearing (20) when the drive magnet (50) rotates.