Abstract: A packaging body for heat processing a material retained therein is basically formed of a plastic base material having side joining sections, and end sides. The side joining sections and end sides are superposed and connected together to form a bag for filling the material. A sealant layer is deposited on at least one of the end sides to connect the end sides together through the sealant layer to thereby form a vapor communication joining section at the end sides. The sealant layer has a peeling off property from 0 to 1,200 gf/15 mm at 90° C. and a peeling off property of equal to or more than 3 kgf/15 mm at a room temperature. Thus, only when the packaging body is heated more than 90° C., the vapor communication joining section is only opened to release pressure inside the packaging body.

Abstract: A packaging body that the fabrication of the bag or filling, tight sealing of the contents and packaging can be easily performed as well as the burst of the packaging body at the time of cooking by heating can be prevented and a packaged food or the like can be manufactured at low cost is provided.