A spindle motor includes a base portion and a bearing mechanism. A fixing region, which includes a first region at which the base portion and the bearing mechanism are fixed to each other and a second region at which a seal gap is defined between the base portion and the bearing mechanism, is located between an inner circumferential portion of the base portion which defines a through hole and an outer circumferential portion of the bearing mechanism. The inner circumferential portion of the base portion has, at least in the second region, a degree of surface roughness greater than a degree of surface roughness of the outer circumferential portion of the bearing mechanism. The seal gap gradually decreases in radial width with increasing height, and includes an adhesive along an entire circumference of the seal gap.