To form a laminated sheet capable of being subjected to retort disinfection and having a good gas barrier property and steam barrier property by laminating a thermoplastic resin layer, a cardboard layer, a barrier layer, and a sealant layer in this order, and bonding the thermoplastic resin layer and cardboard layer and the cardboard layer and barrier layer respectively via a moisture absorption material- blended adhesive.

The laminated sheet 10 is formed such that a thermoplastic resin layer, a cardboard layer 12, a barrier layer 13, a sealant layer 14 are laminated in this order, and the thermoplastic resin layer 11 and cardboard layer 12 and the cardboard layer 12 and barrier layer 13 are bonded respectively by an adhesive 15 with a moisture absorption agent 16 blended therein. The barrier layer 13 is set between the cardboard layer 12 and the sealant layer 14 so as to afford a gas barrier property and steam barrier property to the laminated sheet 10. The sealant layer 14 is a resin layer having a heat sealing property for maintaining a sealing strength and impact resistivity. The adhesive layer 15 is blended with a moisture absorption agent 16 in order to absorb and adsorb moisture contained in the cardboard 12 or moisture absorbed through the thermoplastic resin layer 11 from the external environment.