Disclosed herein is a spindle motor having a fluid dynamic bearing as an oil gap formed between a rotator and a stator, wherein the stator includes a sleeve having a protruding part extending in a circumferential direction formed on the upper part thereof, the rotator includes a hub including an oil interface forming member positioned under the protruding part of the sleeve and coupled to the lower end thereof, and an oil interface of the oil gap is formed between the upper part of the oil interface forming member and the lower part of the protruding part of the sleeve.