To facilitate positioning of a thrust plate based on a shaft and simplify a process to assemble a fluid dynamic-pressure bearing.

The fluid dynamic-pressure bearing system is provided with a thrust plate/shaft integral type member 20 having the shaft 12 and the thrust plate 14. The thrust plate/shaft integral type member 20 is formed by injection molding. Since the shaft 12 and the thrust plate 14 are integrally formed in an assembling process for the fluid dynamic-pressure bearing system and the spindle motor, a relative position relation between the shaft 12 and the thrust plate 14 is not changed, and perpendicurality and coaxiality thereof are constantly kept.