A gap is defined between an inner region of an end face of a first container member of a container and an inner region of an abutting portion of a second container member, the inner regions being situated inside a seal member. The respective inner regions of the end face of the first container member and the abutting portion of the second container member, which are situated inside the seal member, are prevented from coming into contact with each other when the interior of the container is decompressed. Even though the second container member is bent inward by atmospheric pressure when the container is decompressed to a predetermined degree of vacuum, therefore, the abutting portion thereof cannot come into contact with the inner edge of the end face of the first container member. Thus, if decompression and exposure to atmospheric pressure are repeated to bend the container member repeatedly, there is no possibility of the inner edge portion of the end face of the first container member being separated or rubbed off to produce dust.