Abstract: Proposed is a coupler structure of a hand grinder. The coupler structure is fastened to a rotating shaft of a grinder body to enable a machining disc to be more simply and rapidly attached to or detached from the grinder body. Fabrication costs are significantly reduced by simplifying the components associated with the coupler mounted on the rotating shaft of the grinder body. Since the consumable disc is easily attached to and detached from the coupler with one touch, a replacement operation is performed rapidly, thereby significantly improving the efficiency of work.