Embodiments of the invention are directed to keeping a height of a pivot bearing low in order to build a thinner magnetic disk drive. In one embodiment, a ball bearing is provided between a shaft and a sleeve. An inner race of the ball bearing is secured to the shaft through bonding or the like. An outer race of the ball bearing is secured to the sleeve through bonding or the like. A bearing ball is placed between the inner race and the outer race of the ball bearing. A magnet is fitted to the outer race of the ball bearing. A magnet is mounted on a circular plate mounted on one end of the shaft. The magnet is located at a position opposing the magnet mounted on the outer race so as to generate a repulsive force therebetween.