PROBLEM TO BE SOLVED: To provide an oxygen absorbent which is stuck to a food product when performing pillow packaging, which hardly causes the falling and damage of the food product in a packaging step and which exhibits an excellent food preservation effect.SOLUTION: In a packaging bag constituted by thermally sticking the peripheral edge parts of sheets made by the lamination of a packaging material A and a packaging material B so that the inner surfaces of the packaging material B face each other, an oxygen absorbing composition containing iron powders or a reductive organic compound, an alkaline compound and water are encapsulated. An oxygen absorbent has a stiffness value (vertical) at a heat seal portion formed at the peripheral edge part of the packaging bag by thermal adhesion of 3-10 mN and a stiffness value (horizontal) of 1-5 mN. The packaging material A is paper or nonwoven fabric. The packaging material B is a perforated single layer plastic film selected from a group consisting of polyethylene, polyester, polypropylene, nylon, vinylon, cellophane and a vapor deposition film or a non-perforated single layer plastic film having an oxygen gas permeability of 5,000 mL/m24h atm or more.SELECTED DRAWING: Figure 3
