There are provided a spindle motor including a lower thrust member fixed to a base member; and a shaft fixed to the lower thrust member, wherein the lower thrust member includes a fitting protrusion protruding upwardly in the axial direction and fitted into a fixing groove formed in a lower end of the shaft so as to be depressed upwardly in the axial direction, a thrust bearing surface forming a thrust bearing between the thrust bearing surface and a lower surface of the sleeve, and an extension part protruding from an outer edge of the lower thrust member in a radial direction upwardly in the axial direction to form a liquid-vapor interface between the extension part and an outer surface of the sleeve while enclosing the sleeve, and the thrust bearing surface has inner and outer concave parts depressed in one of inner and outer diameter directions thereof, respectively.