To provide a novel packaging bag apparatus for a product which is needed to be tightly closed (sealed) until it is used.

Contents which need tight closing until being used such as fragrance 3, dehumidifier, insecticide, deodorizer, detergent, freshness holding agent, disinfectant and fomentation are put between a surface piece 1 comprising an air permeable material such as a porous film, nonwoven cloth, and paper and a rear piece 2 comprising a non-permeable material such as a synthetic resin film, entire peripheral rims of the surface piece 1 and the rear piece 2 are fixed with such a strength that force of fingers cannot peel off and airtightly to each other, and also a cover piece 4 comprising a non-permeable material such as a synthetic resin film is overlaid on an exterior of the surface piece 1, while the entire peripheral rim of the cover piece 4 is fixed to the entire peripheral rim fixed part of the surface and rear pieces with such a strength that force of fingers can peel off and airtightly.