Device for producing a stacking projection on the inner side (3) of a container wall (4) comprises a splaying mandrel (5) and a support ring (S) open at the top. Those are movable relative to one another between a standby position and a deformation position. The splaying mandrel comprises at least in some places a retaining indentation (9) running externally circumferentially and the support ringcomprises at least in some places a notch projection (10) running internally circumferentially. Through the interaction of those indentation and projection in the deformation position, the stacking projection can be produced, wherein in the deformation, a gap width (11) between in particular the retaining indentation and the notch projection in a border section of the circumference (12) is greater than the gap width (13)between the other circumferential sections. The corresponding container (33) comprises an inner wall (34) and an outer wall (35), in each case narrowing conically downwards. The walls are at least joined together at the upper edge (36) of the container, wherein on the inner side (53) of the inner wall a denesting means (40), protruding inwards, is formed as a stacking projection. On that, another container when inserted in the container is supported. A distance between said stacking projection and the bottom of the projection (46), is at least slightly larger than a distance between said bottom and a potential contact starting point at which the outer container when inserted in the inner container starts to contact the inner side of the inner wall of the inner container.