The provision of an easily laterally opened type paper container includes: a paper base material which is made of material having thermoplastic resin layers on both sides thereof; an opening piece which is formed of a resin film, and sandwiched and bonded between an upper piece and a lower piece of an overlap width portion of the paper base material which is overlapped and laminated on each other with a picking length; a notch portion defined in the upper piece of said overlap width portion in correspondence with both ends of said opening piece laterally; and an oriented polyolefine film having such a characteristic that an orientation magnification of the film in one direction is larger than that in a direction orthogonal to the one direction, which is stacked on an inner surface of the paper container material in such a manner that the one direction having the larger orientation magnification coincides with an opening direction of the paper container.