A centrifugal pump apparatus including a housing having first and second chambers (7, 8) partitioned from each other by a diaphragm, an impeller rotatably provided in said first chamber along said diaphragm, for delivering liquid by centrifugal force during rotation, and a drive unit (18 to 20 or 19, 20 or 41 to 47) provided in said second chamber for driving said impeller to rotate with said diaphragm being interposed, comprising: a first magnetic element (15a, 15b) provided in one surface of said impeller; a second magnetic element (16a, 16b) provided in an inner wall of said first chamber facing the one surface of said impeller, for attracting said first magnetic element (15a, 15b); and a third magnetic element (17 or 40) provided in the other surface of said impeller and attracted by said drive unit (18 to 20 or 19, 20 or 41 to 47), during rotation of said impeller, first attractive force acting on between said first and second magnetic elements (15a, 15b, 16a, 16b) and second attractive force acting on between said third magnetic element (17 or 40) and said drive unit (18 to 20 or 19, 20 or 41 to 47) being balanced with each other substantially in a center of a movable range of said impeller in said first chamber, a first groove for hydrodynamic bearing being formed in one surface of said impeller or in the inner wall of said first chamber facing the one surface and a second groove for hydrodynamic bearing being formed in the other surface of said impeller or in said diaphragm facing the other surface, a sidewall of said first chamber facing a side surface of said impeller being formed cylindrically, and characterised in that a centerline of said second magnetic element (16a, 16b) being arranged position different from that of a centerline of the sidewall of said first chamber such that a rotation centerline of said impeller matches the centerline of the sidewall of said first chamber during rotation of said impeller. a first magnetic element (15a, 15b) provided in one surface of said impeller; a second magnetic element (16a, 16b) provided in an inner wall of said first chamber facing the one surface of said impeller, for attracting said first magnetic element (15a, 15b); and a third magnetic element (17 or 40) provided in the other surface of said impeller and attracted by said drive unit (18 to 20 or 19, 20 or 41 to 47), during rotation of said impeller, first attractive force acting on between said first and second magnetic elements (15a, 15b, 16a, 16b) and second attractive force acting on between said third magnetic element (17 or 40) and said drive unit (18 to 20 or 19, 20 or 41 to 47) being balanced with each other substantially in a center of a movable range of said impeller in said first chamber, a first groove for hydrodynamic bearing being formed in one surface of said impeller or in the inner wall of said first chamber facing the one surface and a second groove for hydrodynamic bearing being formed in the other surface of said impeller or in said diaphragm facing the other surface, a sidewall of said first chamber facing a side surface of said impeller being formed cylindrically, and characterised in that a centerline of said second magnetic element (16a, 16b) being arranged position different from that of a centerline of the sidewall of said first chamber such that a rotation centerline of said impeller matches the centerline of the sidewall of said first chamber during rotation of said impeller.