To eliminate a disadvantage that some paper powder and the like are mixed with a stored item and simplify work for opening a package.

A package 1 is filled with some stored items in a three-side sealed bag comprising a film 5 having a heat melting an adhering characteristic closely sealed by a vertical seal segment, a lower and lateral seal segment 4, and an upper and lateral seal segment 3 having a melting and adhering strength of easy seal opening feature. The package 1 is manufactured by a pillow packaging method, and then the package 1 is stored in an outer box 31 installed on a conveyor 30. This pillow packaging method comprises steps of curving the film 5 intermittently fed out, overlapping both side edges of the film to form the vertical seal segment and cylindrical member 6, filling in sequence the stored items into the cylindrical member 6, forming a melting an adhering segment 8 having a region of high melting and adhering strength becoming the lower and lateral seal segment 4 and a region of weak melting and adhering strength becoming the upper and lateral seal segment 3, and diving the melting and adhering segment 8 into two portions.