There have been presented the papers, No. 1 to No. 4, on the bending theories of the superstructure constructed with ordinary stiffened flat plates. Recently, corrugated plates have begun to be applied to the side wall of the superstructure instead of stiffened flat plates in order to reduce weight of the structure and labour of removing the welding distortion of the wall. In these structures, longitudinal stresses transmitted from main hull girder may be smaller than that in the ordinary ones, because the tensile rigidity of the corrugated plates is much smaller than that of the stiffened flat plates. Then the elastic behaviour of the superstructure constructed with horizontally corrugated plates and vertically corrugated ones were investigated.