Abstract: The present invention provides a packaging bag that can suppress the formation of an opening at a portion other than the vapor release seal portion. According to the present invention, provided is a packaging bag made of a film heat-sealed at a seal portion, wherein the seal portion includes a vapor release seal portion configured to form a vapor flow path as an internal pressure increases, the vapor release seal portion has a curved shape curved toward an inner direction of the packaging bag, the vapor release seal portion includes a first region including a distal end of the curved shape and a second region adjacent to the first region, and sealing strength in the first region is higher than sealing strength in the second region.