A packaging material is formed of a composite film obtained by bonding a first film formed of a resin film and a second film having a stretch ratio lower than a stretch ratio of the resin film forming the first film or formed of a non-oriented resin film. The first film has a linear cut, a predetermined length in the longitudinal direction of the cut, and a predetermined width in a direction perpendicular to the cut. The packaging material includes a first strongly bonded section in which the first film and the second film are firmly bonded and a first weakly bonded section and a second weakly bonded section provided at both sides of the first strongly bonded section, with the first film and the second film being weakly bonded in the first weakly bonded section and the second weakly bonded section.