Spindle motor

A spindle motor comprising:

• a base plate;
• a stator core fixed to the base plate;
• a rotor member rotatable with respect to the base plate;
• a rotor magnet facing the stator core in a radial direction and fixed to the rotor member;
• and
• a ring-shaped magnetic attractive plate attached to a bottom surface of the base plate in a manner to face the rotor magnet in an axial direction and configured to generate a magnetic attracting force between the rotor magnet and the magnetic attractive plate,
• wherein a ring-shaped wall surface is provided on the bottom surface of the base plate,
• at least one of an outer circumference and an inner circumference of the ring-shaped magnetic attractive plate has a polygonal shape formed of a plurality of linear parts and a plurality of corner parts, and
• the ring-shaped magnetic attractive plate is fixed to the base plate with an adhesive in a condition that at least one of the outer circumference and the inner circumference having the polygonal shape is in contact with the ring-shaped wall surface.