PURPOSE: To prevent the removement of a plurality of labels and the damaging of the labels in the case when the thin plastic labels are used by moving a vacuum cup at a controlled slow speed when the labels are removed.

CONSTITUTION: In a blow molding device, a plurality of parisons are extruded onto the neck molds 21 on a head 22 from an extruder 20, and the head 22 is moved upwardly when the extrusion is connected to define the parisons P. The mold sections 23 form an array of cavities C, and are closed around the parisons, and then the parisons are blown outwardly to form the hollow articles. Two arrays of label picking devices 25 supporting the vacuum cups are mounted on the head, and moved inwardly so that the head can be moved downward between the mold sections, then a pressure reducing device is moved outwardly to place the labels in the mold cavities C, and the reduced pressure is kept till the mold sections 23 are closed and the parisons P are expanded to form the hollow article. As a result, the removement of a plurality of labels and the damaging of,labels can be prevented when the labels are made of plastic.