PURPOSE: To provide a bag with a window having an increased goods value without shrinks nor waves in the surrounding of a window range by a method wherein a laminated film which is uniform all over the surface without any stepped parts due to differences in the thickness in the surrounding of the window range and along a border line with an opaque film is made into a good- finished bag without any loss.

CONSTITUTION: In a window range 3 of a transparent film 2, a protruding part 2a in which the thickness is increased by an amount corresponding to a thickness 6 of an untransparent film 5 is formed, and the opaque film 5 is laminated on the transparent film 2 on the protruding part 2a side excluding the window range 3.