Provided is a packaging container including a bag main body portion having a first surface, a second surface and an opening portion; and a tongue piece portion formed to be continuously extended from the first surface. The bag main body portion and the tongue piece portion have an aluminum vapor-deposited layer on an outside thereof, the packaging container further includes an adhesion portion which is provided on the second surface to be spaced from the opening portion; and a folded-back portion which is provided between the adhesion portion and the opening portion to fold back the tongue piece portion to the opening portion side. A length of the tongue piece portion is a, a length from the opening portion to the folded-back portion is b, and a length from the folded-back portion to the adhesion portion is c. And,

a