Magnetic suspension bearing (10; 30; 40; 50) comprising: - a part rotatable about a rotation axis and a fixed part, - two elements (14, 42, 52, 90, 122, 172, 16, 34, 44, 56, 124, 128, 162), a first element and a second element, made out of ferromagnetic material, one (14, 42, 52, 90, 122, 172) integral with the rotatable part and one integral with the fixed part (16, 34, 44, 56, 124, 128, 162) which are closely placed, separated by an air gap, and have axial symmetry with respect to said axis, - a magnetic flux generator for generating a magnetic flux inside the two elements; wherein the two elements have such a shape that the magnetic flux, flowing inside the two elements, describes in space a torus and passes from one element to the other through the air gap along a direction orthogonal to the direction of a load applied to the bearing, characterized in that (a) the first element is annular, has a U-shaped cross-section, and the flux generator is placed on one wall of the air-gap, the wall belonging to the first element, or (b) the first element is annular and is formed by two elements between which the flux generator, constituted of a permanent magnet with a polar axis parallel to the rotation axis, is placed, so that the magnetic flux passes through said two elements of the first element and the gap in air, and closes inside the second element. - a part rotatable about a rotation axis and a fixed part, - two elements (14, 42, 52, 90, 122, 172, 16, 34, 44, 56, 124, 128, 162), a first element and a second element, made out of ferromagnetic material, one (14, 42, 52, 90, 122, 172) integral with the rotatable part and one integral with the fixed part (16, 34, 44, 56, 124, 128, 162) which are closely placed, separated by an air gap, and have axial symmetry with respect to said axis, closely placed, separated by an air gap, and have axial symmetry with respect to said axis, - a magnetic flux generator for generating a magnetic flux inside the two elements; wherein the two elements have such a shape that the magnetic flux, flowing inside the two elements, describes in space a torus and passes from one element to the other through the air gap along a direction orthogonal to the direction of a load applied to the bearing, characterized in that (a) the first element is annular, has a U-shaped cross-section, and the flux generator is placed on one wall of the air-gap, the wall belonging to the first element, or (b) the first element is annular and is formed by two elements between which the flux generator, constituted of a permanent magnet with a polar axis parallel to the rotation axis, is placed, so that the magnetic flux passes through said two elements of the first element and the gap in air, and closes inside the second element. wherein the two elements have such a shape that the magnetic flux, flowing inside the two elements, describes in space a torus and passes from one element to the other through the air gap along a direction orthogonal to the direction of a load applied to the bearing, characterized in that (a) the first element is annular, has a U-shaped cross-section, and the flux generator is placed on one wall of the air-gap, the wall belonging to the first element, or (b) the first element is annular and is formed by two elements between which the flux generator, constituted of a permanent magnet with a polar axis parallel to the rotation axis, is placed, (a) the first element is annular, has a U-shaped cross-section, and the flux generator is placed on one wall of the air-gap, the wall belonging to the first element, or (b) the first element is annular and is formed by two elements between which the flux generator, constituted of a permanent magnet with a polar axis parallel to the rotation axis, is placed, so that the magnetic flux passes through said two elements of the first element and the gap in air, and closes inside the second element.