Abstract: An impact energy absorbing structure includes an outer-shell structural member having a hollow portion, and a porous element filling the hollow portion of the outer-shell structural member and capable of collapsing while keeping a reaction force produced by the porous element constant from an early stage of application of a compressive stress. A partition wall having a through opening formed therein is provided in the hollow portion of the outer-shell structural member. The partition wall is located on one side of the porous element, opposite to the other side to which the compressive stress is applied, so as to ensure improved impact energy management and high-response structural crash behavior.