To provide a spindle motor wherein shaft runout can be stably prevented, even at a high speed revolution.

A magnet M for energization is formed annular in shape and is magnetized in two poles so that the areas defined by lines at 180° to the center of the ring are heteropolar in the direction of the rotating shaft. The magnet is installed at the rotor-side end 14a of a bearing housing so that it faces the top face 1b of a rotor yoke made of magnetic material, when a rotor R is assembled to a stator S by inserting the rotating shaft 3 into a bearing 15, so that the center of the magnet coincides with the center of the rotating shaft.