Abstract: A side-gored bag is provided which includes: a first panel film, a second panel film; a pair of V-members forming side gussets; and a zipper device including a first zipper tape, and a second zipper tape. The upper edges of the V-members are situated so as to be downwardly displaced by a distance w from the upper edges of the first and second panel films. The first zipper tape has a first meshing rib and the first zipper tape is bonded in a horizontal position to the first panel film over an area of the panel film which extends by a distance W (wherein W>w) from the upper edge in such a manner that both the lower side of the zipper tape and the first meshing rib are situated below the upper edges of the V-members so as to cover an upper part of each V-member. The second zipper tape has a second meshing rib and the second zipper tape is bonded to the second panel film in such a manner that the second meshing rib is aligned with the first meshing rib.