A first shock absorber group is obtained by combining a plurality of shock absorber blocks, absorbs a shock in a direction parallel to an end surface of a cask, consisting of a first material. A second shock absorber group absorbs the shock in a direction perpendicular to or oblique with respect to the end surface, consisting of a second material having a weaker compressive strength than the first material. A third shock absorber group absorbs the shock in a direction perpendicular to the end surface, consisting of a third material having a weaker compressive strength than the second material. A space is provided at least in the first shock absorber group.