Abstract: A casing comprises a main body provided with a first fringe that is protruded outwardly from the outer periphery of the opening and a lid provided with an engaging part to be coupled with the first fringe and a second fringe that covers the first fringe. A finger lug is formed on a part of the side wall of the second fringe on the lid. A recess is formed in the rear side of the finger lid to receive an inserted finger. The finger tip can be operated to release the engagement between the first fringe of the casing main body and the engaging part of the lid when the finger tip is placed in the recess.

Abstract: A case for packaging, manufactured according to the present invention, comprises a case body and a lid that engages with the case body, an engaging tab attached to the case body side and protruding outwardly, a slot attached to the lid side in such a manner that the engaging tab can be inserted in the slot, the outer surface of the engaging tab being formed of a first elevated face that protrudes substantially laterally to the direction of protrusion of the engaging tab, a step-gap part provided on the rear side, the outer surface of an edge part on the case body side that is positioned opposite to the engaging part, being formed of a second elevated face that protrudes in the same direction as the direction of protrusion of the first elevated face, the second elevated face being provided with a major cut line into which the engaging tab can be inserted longitudinally to the second elevated face, and sub cut lines that start at both ends of the major cut line towards the inside.