The disclosure provides a torsional damper having a hub in which a boss adapted to be fixed to a rotating shaft, such as a crankshaft of an engine, and an annular rim are integrally provided via a plurality of stays, and an annular vibration ring connected to an outer circumferential surface of the rim via an elastic body. The stays have a circumferential width dimension that does not exceed one-quarter of the wavelength of the axial resonant frequency of the hub, and are thickened within a range in which the axial thickness dimension does not exceed one-half of the wavelength of the axial resonant frequency of the hub. Thickening of the stays is implemented by, for example, setting the axial thickness dimension thereof to a length equal to or more than one-quarter of the wavelength of the axial resonant frequency of the hub. The stays have an axially inclined shape.