Peel-openable package and opening structure for peel-openable package

A peel-openable package, comprising:

• a package main body having a content enclosed therein, at least a part of the package main body including:
• an inner member located at a position corresponding to an inner portion of the package main body;
• and
• an outer member bonded to a surface of the inner member, the surface corresponding to an outer portion of the package main body;
• wherein:
• the inner member and the outer member have a foldable portion in an area thereof where the inner member and the outer member are folded to be bonded together;
• the foldable portion includes a peel region where the inner member and the outer member are allowed to be peeled off from each other thereby forming a through-hole that passes through the inner member and the outer member when the inner member and the outer member are folded to be bonded together;
• the foldable portion includes a cutout, in the peel region, in each of the inner member and the outer member, the cutouts extending so as to cross a direction corresponding to a folding direction in which the foldable portion is folded, and the cutouts each being formed into the through-hole passing in a thickness direction through the inner member and the outer member when the foldable portion is folded;
• the cutout formed in the inner member and the cutout formed in the outer member are away from each other by a predetermined interval, the predetermined interval extends in the direction corresponding to the folding direction, and the cutouts formed in the inner member and the outer member comprise a stair-shaped inner wall of the through-hole;
• facing surfaces of the inner member and the outer member facing each other are bonded together by an adhesive layer provided between the facing surfaces such that the facing surfaces are peelable from each other, the facing faces being defined in at least the peel region;
• a sealing member is provided between the facing surfaces, of the inner member and the outer member, defined in the peel region, the sealing member being broken when the inner member is folded at a predetermined angle or greater;
• and
• the sealing member is located on a surface of the inner member that is to be a peak-side surface when the inner member is folded, and covers the cutout formed in the inner member.