A seal base, which is thicker than a thick portion and is bondable to an inner surface of a bag body, is continuously connected to one of belt-like bases of a zipper tape via a belt-like cutting portion that is thinner than the thick portion and separates a containing space from an outside. A first linking portion having a first corner (a) is defined by a cutting outer surface of the cutting portion and a seal outer continuous surface of the seal base. A second linking portion having a second corner (b) is defined by a contained cutting surface of the cutting portion and a contained seal continuous surface of the seal base.