PURPOSE: To tear a film easily while increasing the film weld strength by a method wherein film rims of a cylindrical package are aligned together and welded so that the rims form the second weld line along the outer face of a cylindrical package, and a cut is made on the second weld line.

CONSTITUTION: Rims 1a and 1b of a film 1 are joined with inner surfaces facing each other which is an extension of an inner wall of a cylindrical package 10, and aligned together. The aligned portion is welded along a first weld line S1. The film rims 1a and 1b protruding from the first weld line S1 are bent in one direction and aligned to an outer surface of the package 10. Three films, the film rims 1a and 1b and the film 1 which composes the package 10 are welded together on a second weld line S2 by high frequency or supersonic wave. The second weld line S2 has a cut 1 (a portion not welded) on its mid and a notch is placed at 1. This allows easy tearing of the film while strengthening the weld portion.