A damping structure of a hard disk drive. The damping structure includes: a damping plate arranged spaced apart from an upper surface of the cover member, such that an air gap is formed between the cover member and the damping plate; and a damping member arranged between an edge of the cover member and an edge of the damping plate. The damping plate includes a stepped portion which is inwardly formed at a portion spaced apart from the edge of the damping plate by a predetermined distance, and a bent portion which is formed at an edge of the damping plate and smoothly bent toward the cover member. In such a damping structure, an impact that is applied to the cover member from an outside can be reduced much more through the damping plate and the damping member.