Disclosed is a centering device of a spindle motor. The centering device includes a body portion which is disposed on the rotor of the spindle motor, and which is provided with a central hole for accommodating the shaft of the spindle motor; and a plurality of centering elastic finger units, located along the periphery of the body portion. Each centering elastic finger unit includes at least two elastic fingers. Each elastic finger includes a free end which extends from the body portion in the circumferential direction of the rotor, and which has a contact portion adapted to urge against an optical disk to guide the centering of the optical disk with respect to the shaft of the spindle motor. Preferably, the contact portion is formed into an arc surface so as to reduce the contact area and thus the friction between the elastic fingers and the disk.