A centrifugal pump apparatus including a housing having first and second chambers (7, 8) partitioned from each other by a dividing wall, an impeller rotatably provided in said first chamber along said dividing wall, for delivering fluid by centrifugal force during rotation, and a drive unit (18 to 20) provided in said second chamber for driving said impeller to rotate with said dividing wall being interposed, comprising: a first magnetic element provided in one surface of said impeller; a second magnetic element provided in an inner wall of said first chamber facing the one surface of said impeller, for attracting said first magnetic element; and a plurality of third magnetic elements provided in the other surface of said impeller, arranged in a direction of rotation of said impeller, and attracted by said drive unit (18 to 20), wherein said drive unit (18 to 20) includes a plurality of coils provided to face said plurality of third magnetic elements, for generating rotating magnetic field, wherein the drive unit further includes a plurality of fourth magnetic elements provided in correspondence with said plurality of coils respectively and each inserted in the corresponding coil, during rotation of said impeller, first attractive force between said first and second magnetic elements (15, 16) and second attractive force between said plurality of third magnetic elements and said plurality of fourth magnetic elements are balanced with each other substantially in a center of a movable range of said impeller in said first chamber, and a first groove for hydrodynamic bearing is 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 is formed in the other surface of said impeller or in said dividing wall facing the other surface, wherein said drive unit (18 to 20) further includes a disc-shaped fifth magnetic element, said plurality of coils are provided between said dividing wall and said fifth magnetic element, and said plurality of fourth magnetic elements are joined to said fifth magnetic element, the centrifugal pump apparatus being characterised in that: each of said fourth magnetic element is shorter than the corresponding coil in a direction of a central axis of said impeller. a first magnetic element provided in one surface of said impeller; a second magnetic element provided in an inner wall of said first chamber facing the one surface of said impeller, for attracting said first magnetic element; and a plurality of third magnetic elements provided in the other surface of said impeller, arranged in a direction of rotation of said impeller, and attracted by said drive unit (18 to 20), wherein said drive unit (18 to 20) includes a plurality of coils provided to face said plurality of third magnetic elements, for generating rotating magnetic field, wherein the drive unit further includes a plurality of fourth magnetic elements provided in correspondence with said plurality of coils respectively and each inserted in the corresponding coil, during rotation of said impeller, first attractive force between said first and second magnetic elements (15, 16) and second attractive force between said plurality of third magnetic elements and said plurality of fourth magnetic elements are balanced with each other substantially in a center of a movable range of said impeller in said first chamber, and a first groove for hydrodynamic bearing is 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 is formed in the other surface of said impeller or in said dividing wall facing the other surface, wherein said drive unit (18 to 20) further includes a disc-shaped fifth magnetic element, said plurality of coils are provided between said dividing wall and said fifth magnetic element, and said plurality of fourth magnetic elements are joined to said fifth magnetic element, the centrifugal pump apparatus being characterised in that: each of said fourth magnetic element is shorter than the corresponding coil in a direction of a central axis of said impeller.