To provide a packaging bag, which is deaerated smoothly and retains sufficient adhesion strength while material loss is reduced.

According to the packaging bag, a heat sealing part 4 having non-sealing parts 3 for deaeration is formed on the periphery of two sheets 1, 2 overlapping each other. At the heat sealing part 4, an interposing sheet 5 is inserted between the sheets 1, 2, and has heat shrinkability that makes it shrink longitudinally by heat applied upon heat sealing the heat sealing part 4. The interposing sheet 5 is narrower than the heat sealing part 4 and is within the area that is covered with the interior of the heat sealing part 4. The interposing sheet 5 is a film having surface with irregularities.