In order to allow a bag to be easily unsealed by sliding both sides of the bag in a longitudinal direction of a zipper tape irrespective of the rigidity of the zipper tape, a zipper-tape bag according to an aspect of the invention includes: a bag body including at least a pair of facing surfaces; and an elongated zipper tape whose cross sectional profile includes first and second bases each bonded to corresponding one of facing surfaces, and mutually engageable first and second engagement portion respectively protruded from the first and second bases, the zipper tape including an intermediate hinge at at least one point in the longitudinal direction.