A pivot shaft fixing structure of a data storage device includes a projection hole formed through a top surface of a pivot shaft that rotatably supports an actuator. In addition, a projection protrudes from a bottom surface of a cover member and fits into the projection hole. Furthermore, a deformable member is disposed around at least a portion of the projection and is disposed between the bottom surface of the cover member and the top surface of the pivot shaft. The pivot shaft fixing structure is advantageously applied within a hard disk drive.