A sealed tank incorporated in a polyhedral bearing structure, said tank comprising a plurality of tank walls including a first wall and a second wall that are parallel to a first direction of said tank and spaced apart in a second direction of said tank, the tank walls further including two end walls orthogonal to the first direction of the tank and connecting the first wall and the second wall, possibly via first intermediate walls arranged between the first wall and the two end walls and/or via second intermediate walls arranged between the second wall and the two end walls, each tank wall being borne by a corresponding bearing wall of the bearing structure, each tank wall having a multilayer structure successively comprising, in the thicknesswise direction from the outside to the inside of the tank, a thermally insulating barrier held against the corresponding bearing wall and a sealing membrane borne by the thermally insulating barrier, the sealing membrane of each of the first wall, the second wall and the end walls comprising a series of corrugations that are parallel to one another and at right angles to transverse corners parallel to a third direction of the tank and formed at the intersections between the first wall or the second wall, the end walls and, if necessary, the intermediate walls arranged between them, the parallel corrugations being spaced apart so as to form, in the third direction: - a plurality of identical regular intervals, each regular interval being formed between two adjacent corrugations, and - at least one singular interval different from the regular interval, characterized in that the at least two adjacent corrugations spaced apart by the singular interval are continued uninterrupted at at least three of said transverse corners, preferably at a number of transverse corners greater than half of a total number of the transverse corners. each tank wall having a multilayer structure successively comprising, in the thicknesswise direction from the outside to the inside of the tank, a thermally insulating barrier held against the corresponding bearing wall and a sealing membrane borne by the thermally insulating barrier, the sealing membrane of each of the first wall, the second wall and the end walls comprising a series of corrugations that are parallel to one another and at right angles to transverse corners parallel to a third direction of the tank and formed at the intersections between the first wall or the second wall, the end walls and, if necessary, the intermediate walls arranged between them, the parallel corrugations being spaced apart so as to form, in the third direction: - a plurality of identical regular intervals, each regular interval being formed between two adjacent corrugations, and - at least one singular interval different from the regular interval, - a plurality of identical regular intervals, each regular interval being formed between two adjacent corrugations, and - at least one singular interval different from the regular interval, characterized in that the at least two adjacent corrugations spaced apart by the singular interval are continued uninterrupted at at least three of said transverse corners, preferably at a number of transverse corners greater than half of a total number of the transverse corners.