In a device for shaping a flat blank (46) made of cardboard into a container (48), comprising a shaping tool (50) and a ram (10) which can be moved in a primary shaping direction (z) into the shaping tool (50) so as to erect the flat blank by means of the shaping tool (50), at least two lateral walls (18) which can be pivoted about a respective pivot axis (s) located transversely relative to the primary shaping direction (z) are hinged to the ram (10), whereby a main surface defined by the free end edges (19) of the lateral walls (18) can be adjusted. In order to carry out a pivoting motion, the lateral walls (18) are seated in a non-positively sliding manner against wedge elements (28) by means of pretensioned spring elements (22, 24), the wedge elements being displaceable in the primary shaping direction (z).