An actuator supporting apparatus of a hard disk drive includes a pivot bearing including an inner ring, an outer ring, and a rolling member, which are installed coaxially, to support an actuator arm to pivot. The actuator supporting apparatus also includes a support structure to support upper and lower surfaces of the inner ring, and a buffer member interposed between at least one of the upper and lower surfaces of the inner ring and the support structure, to buffer vibrations and impacts. Thus, a feature of buffering vibrations and impacts by the buffer member is not changed and is constantly maintained, regardless of accumulation of manufacture allowance or a change in the environment. Also, a problem in reliability of a product due to deterioration of structural strength, which occurs in the conventional actuator supporting apparatus, does not occur in the actuator supporting apparatus of the present invention.