A method of producing a packaging structure, including the steps: coating at least one surface of a first sheet base material and/or a second sheet base material with a synthetic polyisoprene latex having a weight average molecular weight of 500,000 -5,000,000 and/or a styrene-isoprene-styrene block copolymer having a weight average molecular weight of 100,000-300,000, sandwiching an article to be packaged in a state wherein the first and second sheet base material are in contact with each other via a latex coated surface formed on the first and/or second sheet base material to thereby obtain a laminated body, pressing a portion where at least the first and second sheet base material of the laminated body are in contact with each other via the latex coated surface at a temperature of 100° C. or less to thereby obtain a pressed laminated body, and performing a sterilization treatment on the pressed laminated body.
