The present invention relates to a spindle motor comprising: a base member of a magnetic material; a lower thrust member installed in the base member; a shaft fixed in the base member or the lower thrust member; a sleeve for forming a thrust compression bearing between the sleeve and the lower thrust member by being arranged on the lower thrust member and for rotatably supporting the shaft by fluid dynamic pressure; and an upper thrust member fixed on the sleeve and a rotor hub rotated with the sleeve and for forming the thrust compression bearing between the sleeve and the upper thrust member in the rotation of the sleeve. Upward thrust compression formed between the lower thrust member and the sleeve can be larger than downward thrust compression formed between the upper thrust member and the sleeve.
