Airbag

The invention provides an airbag includes on an area of a circumferential wall penetrating mounting holes a reinforced area that has a laminated structure of base cloths composed of a body cloth and three pieces of reinforcing cloths overlaid on the body cloth. The base cloths for composing the body cloths and the reinforcing cloths has an adhesive layer on one surface by coating adhesives, and when performing adhesive, heating the adhesive layer only coated on single face opposite to each other for melting to splice the two base cloths to each other. The two base cloths adhesive are composed of two base cloths adjacent to each other by disposed with intervel base cloths of non-disposing section. All the base cloths for airbags of the overlaid area are restricted to offset along a direction orthogonal to the overlaid direction, and using the adhesive area of the base cloths to joint with each other. Even the structure of the circumferential wall of the airbag is formed into structure of overlaid area by overl