Abstract: A water container comprises a bag body formed of a flexible material and a stopper means formed of a synthetic thin resin film. The stopper means is in the tubular form provided with a water inlet opening and a valve opening as well as a belt-like sealing on a portion except for the openings, and is attached into the bag body in such a manner that the inlet opening is open on the bag body and other portion is located within the bag body.The valve opening is smaller in size than the inlet opening, and is positioned on a line extending from at least a portion of the sealing.