A damper 3A is provided with an inner peripheral waveform portion 11 and an outer peripheral waveform portion 12. A flat portion 10 is provided between the inner peripheral waveform portion 11 and the outer peripheral waveform portion 12. When the damper is used for a loudspeaker, the flat portion 10 does not elastically deform in a radial direction R, so that linearity of the damper 3A in a vibrating direction Z is ensured by elastic deformation of the waveform portions. In addition, a rolling phenomenon of a voice coil bobbin and a diaphragm can be suppressed.