Abstract: A method and device for manufacturing a content-filled bottle having an inversion part at its bottom. In producing the bottle, the inversion part is inverted to prevent deformation of a body part caused by a pressure reduction in the bottle, and as a result, inappropriate deformation and buckling of the bottle are prevented, enabling efficient manufacturing of the bottle with high quality. The bottle (3) is held from the outside by an empty-bottle chuck (41) of auxiliary device mounting means in such a way that the bottle (3) is held at its a mouth part (4) by the chuck along the upper surface of a flange part (10) of the bottle (3). Next, an empty-bottle support table (42) on which an assistance device (24) is placed is raised, the assistance device (24) is mounted on a bottom part (7) of the bottle (3), and the bottle (3) is placed on the empty-bottle support table (42).