To manufacture a multi-pocket bag of stable quality at a stable speed without re-constructing an existing bag-making step (bag-making machine).

The width of a "pasting margin" of an envelope-type bag is increased, and a U-shaped adhesive 7 is applied thereto, thereby forming the multi-pocket paper bag characterized by forming a second pocket. The size of the second pocket part (9) is determined by the width and height of the U-shape applied to the pasting margin. Therefore, the width of the pasting margin requires a width equal to or more than the width necessary for the pocket and the width of the adhesive. The depth of the pocket can be increased up to the height (11) of the bag if a second pocket bottom part 10 of the U-shaped adhesive is not applied.