PURPOSE: A stopper is provided to enable complete filling of contents by preventing the volume interference of the contents accommodated inside a vessel. CONSTITUTION: A bubble generation part (200) is forcibly inserted into a part penetrated by a packing (210). Protrusions are integrally formed at the outer periphery of a bubble generation upper part (220) and a bubble generation lower part (221) for the packing to be inserted between the protrusions. Mesh networks (240) are respectively formed at end parts of the bubble generation lower part. An inlet hole (230) is protruded to the packing lower surface of the bubble generation part.
