A container, in particular a plastic ampoule produced using a blow molding process, and filled and closed in the production mold, has a sleeve-shaped neck part (4) connected to a container body (2) as an axial extension. The neck part forms a seat (6) for a preformed insert (8) extending along the axis (12) of the neck part (4), and is formed in the production mold, on a peripheral region (14) of the insert (8). At least one sealing element (42； 68) is provided on the insert (8). The sealing element forms a seal in a sealing region surrounding the axis (12), in combination with a contact surface (38) formed on the seat (6) of the neck part (4).
