Abstract: A sealed laminated vessel is formed from a barrel composed of a laminate including a paper substrate and a metal foil with inner and outer heat-sealable resin layers on both surfaces lapped together to form a straight side seam and a lid member on at least one open end thereof formed from a laminate of a metal foil and heat-sealable resin layer which is heat sealed to a circumferential end edge portion of the barrel. The vessel is formed by a process which includes forming a flat circumferential end portion of the barrel by bending at least one open end of the barrel outwardly and thereafter inwardly bending a part of the bent portion in the reverse direction so that it is lapped on the lower side of the remaining part of the bent portion to form a flat circumferential end portion on at least one open end of the barrel.The lid member is thereafter heat-sealed to the circumferential portion of the barrel through the heat-sealable resin layer of the lid member.