PURPOSE: To make a lid detachable by merely moving a member, keep the container clean, make it being able to open and close freely, and prevent deterioration by continually pressing a sealing member between the neck of the container and the glass lid.

CONSTITUTION: When engaging an inner piece 6 with a lower part of a rim 7 by lifting a lever 9, the lid engages a little slantwise with the neck of the container. Then the cam part of the lever 9 is engaged with the rim 7 by pulling down on the lever 9 while pressing from the upper side. When pulling the lever further down, the covering member is constantly subject to a downward force through a pin 14 and a projection 8, and results in pressing down an annular rubber 4 sandwiched between the lid and container. When the lever 9 is fully pulled down, a stopper 11 at the cam portion of the lever 9 is hitched by the rim 7 of the container to sufficiently press the annular rubber 4. Because this position of the lever 9 is most stable, force to tighten the projection 8 increases no matter which direction the lever 9 moves to, the lid is very hard to come off as a result.