Abstract: An impact energy absorbing member is provided within a vehicle door, and due to impact load from an exterior, the impact energy absorbing member plastically deforms so as to absorb impact energy. The impact energy absorbing member includes a plurality of ribs whose respective surface directions are provided substantially along an impact load direction. Ends of the plurality of ribs are fixed to predetermined positions within the vehicle door. Reduced cross-sectional area portions are provided at fixed end sides of the plurality of ribs. The reduced cross-sectional area portions are provided such that cross-sectional areas of the plurality of ribs along a direction orthogonal to the impact load direction become smaller toward the fixed end sides of the plurality of ribs from lengthwise intermediate portions of the plurality of ribs whose lengths run along the impact load direction.