To secure high sealability and hygiene and also enable easy opening/ closing by forming a cylindrical-face-like lid sealing face formed to be fitted into an inner diameter part of a container mouth at the time of closing a lid and a cylindrical-face-like container sealing face to be in tight contact therewith.

A cylindrical sealing part 11 extending in an axial direction is integrally formed on a rear of a disk-like bottom 6a of a lid member 6. A lid sealing face 11a being an outer peripheral face of the sealing part 11 is formed in an outer diameter size which can be tightly fitted with a container sealing face 2a which is a cylindrical inner peripheral face of a container mouth 2. A fixing member 4 is brought into contact with the outside of the container mouth 2 and strongly pushed down, thereby fitting the lid member 6 into a container 1. This push-down allows an engaging protrusion 15 formed on an inner peripheral face of the fixing member 4 and an engaging recess 16 formed on an outer peripheral face of the mouth 2 to be fitted with each other. Since the lid sealing part 11a and the container sealing face 2a are airtightly attached at this time, leakage and deterioration due to contact with an atmosphere of contents can be prevented.