To achieve a buffer structure corresponding to the refinement of a portable electronic device due to miniaturization and increase in functions.

A granule 4 which is a magnetizable elastic body, a sheet-like magnetic member 3, and a rib 5 are arranged in a hollow outer shell 2. When the housing 1 of an electronic device receives an impact, impact energy is relaxed by the elastic friction of the granule 4 that has elastic property and magnetic force between the granules 4 magnetized by the magnetic member 3. The rib 5, protruding in the outer shell 2, transmits an impact received by the outer shell 2 to the granule 4, and consequently, a more effective buffer effect is obtained; and further, the shape of the outer shell, changed by the impact, can be returned to the original shape by the user's hand, since the granules 4 are aggregated by magnetic force.