In a speaker damper, art sections are disposed on warp reference lines and warp reference lines. Straight sections are disposed so as to intersect intermediate reference lines at right angles. By adopting this configuration, wave parts can be adjusted so that they are less likely to expand/contract on the warp reference lines and the warp reference lines in comparison with related-art concentric circular wave parts. Further, the wave parts can be adjusted so that they are more likely to expand/contract on the intermediate reference lines. In this way, the speaker damper can perform uniform vibrating motions throughout the entire speaker damper with a simple configuration.