To prevent a packaging container surface which can the printed, from being narrowed and also prevent the possibility of the external design from being restricted, by inputting invisible information at every specified interval on a packaging material which is formed tubular in sequence.

A continuous paper-tease packaging material 1 with folds on which invisible information or register marks are given by use of red ink for instance at every specified interval is drawn out of a packaging material reel 2 and formed to make a tubular packaging material 3 by a molding ring and charge a liquid food therein through a charging pipe 10. The invisible information (register mark) put on the packaging material 1 is sensed by an infrared sensor A to correct the position of a design and then, lateral line seals are applied at every certain distance in the crossing direction of the tubular packaging material 3' in which a liquid food is charged by a jaw unit. The space between the upper and lower lateral seals is cut off by a knife to form a pillow- form primarily formed container 4.