The invention relates to a method and an apparatus for the processing of a material web to convert the same to individual packing containers filled with contents. Flexible packing containers for milk or other beverages are manufactured from tubular material which is filled with contents, formed and divided to packing containers with the help of alternately working forming and sealing jaws which are given a reciprocating movement in the longitudinal direction of the tube and in the transverse direction of the tube. In accordance with the invention the jaws are guided and driven by guiding and driving rods which run parallel with the material tube and to which different reciprocating movements are imparted.