The present invention includes a neck mold 53 for forming the outer surface of a neck part 21 of a hollow article 20, an injection cavity mold 54 for forming the outer surface of a torso part 22 of the hollow article, and an injection core mold 55 for forming the inner surface of the hollow article 20. The injection core mold 55 comprises: an outer core mold 59 for forming the inner surface of theneck part 21 which includes an inner screw part 25, the outer core mold being capable of rotating along the inner screw part 25 while moving along the rotational axis thereof; and an inner core mold60 for forming the inner surface of the torso part 22 of the hollow article 20, the torso part having a smaller diameter than the neck part 21, and the inner core mold being capable of linearly movinginside the outer core mold 59 along the rotational axis.