To facilitate attachment-detachment of a drum; and to require not much time, in a holding device for holding the drum, when cutting a metallic thin drum in a round slice shape.

This holding device is provided with a first tapered member 3a and a second tapered member 3b in the shape divided into two parts by cutting a cylindrical member capable of inserting a rotatingly driven support shaft S in a tapered shape in the axis direction. These first tapered member 3a and second tapered member 3b are made relatively movable in the axis direction. Respective tapered surfaces 5a and 5b are made to freely abut or separate. The respective tapered surfaces 5a and 5b are combined by abutting on each other to be formed in a cylindrical shape. First and second ring-like members 4a and 4b capable of fitting a mating side tapering-off tip part, are arranged in a base end part of the first and second tapered members 3a and 3b.