An apparatus for producing at least one container, in particular in ampoule form, made of thermoplastic material, includes a mold (13) with mold components (15, 17). A first calibrating mandrel (19) and a second calibrating mandrel (23) are movable coaxially in relation to the longitudinal direction (21) of the container (1) and in relation to one another. The first calibrating mandrel (19) through the container (1) located in the mold (13) and the second calibrating mandrel (23) from the outer side of the container (1), move into a shaping position in which they calibrate a bottom area that forms at least part of a container bottom between the mandrel ends. A severing device has a movable cutting or punching surface (37) to sever excess plastic material forming during the shaping process in interaction with a cutting or bearing edge on the mold components (17) assigned to the bottom region. The severing device has a cutting device (35) that is guided in an axially displaceable manner on the second calibrating mandrel (23), forms the cutting or punching surface (37) and can move between the withdrawn position and the punching position independently of the movement of the respective calibrating mandrel (23).