AIRBAG AND SUPPORT DEVICE

An airbag includes: a welding portion that bonds peripheral edges of a pair of sheet portions to each other to form a bag shape, in which the airbag is formed to have a pair of holding portions that holds a held body portion therebetween, and at least one of the two sheet portions is formed with a pair of melting portions extending in directions away from mutually facing portions of the two holding portions in the welding portion.