Abstract: An airtight container including a container body having a neck with an opening at one end, a cap having inside a portion having a convex lower end side and attaches to the neck, and a packing. A vertical cross-section of a mouth of the opening forms an upwardly convex curve. The packing has a first concave portion formed on the outer rim of the upper surface, a second concave portion formed on the lower surface sharing a bottom with the first concave portion, and a bent portion radially outboard of the center of the packing and radially inboard of the first and second concave portions are formed, to generate stress that widens the first concave portion and narrows the second concave portion when the cap is attached and the inner surface of the second concave portion is contacted against the mouth of the opening of the neck.

Abstract: An airtight container including a container body having a neck with an opening at one end, a cap having inside a portion having a convex lower end side and attaches to the neck, and a packing. A vertical cross-section of a mouth of the opening forms an upwardly convex curve. The packing has a first concave portion formed on the outer rim of the upper surface, a second concave portion formed on the lower surface sharing a bottom with the first concave portion, and a bent portion radially outboard of the center of the packing and radially inboard of the first and second concave portions are formed, to generate stress that widens the first concave portion and narrows the second concave portion when the cap is attached and the inner surface of the second concave portion is contacted against the mouth of the opening of the neck.