Disclosed is a bag comprising a bag-shaped container body which is made of a flexible film, and a spout tube which allows the inside of the container body to communicate with the outside the container body, wherein the container body comprises: a cylindrical barrel portion； a first sealing part which is formed at a lower end of the barrel portion by matching and sealing together inner surfaces of the film constituting the container body； and a flat bottom face part including an upper end edge of the first sealing part； wherein the spout tube is interposed between the films that are matched at the first sealing part of the bottom face part； and wherein the first sealing part and the spout tube are disposed in a plane which is approximately parallel to the flat bottom face part.
