A hollow article is molded in a state where an inner surface of a neck portion including an inner screw portion is held by an inner neck mold, and then, the hollow article is demolded from the inner neck mold by inserting an ejection rod into the hollow article to be engaged with an inner surface of the hollow article and rotating the hollow article together with the ejection rod.

A hollow article 10 is molded in a state where an inner surface of a neck portion 11 including an inner screw portion is held by an inner neck mold 52, and then, the hollow article 10 is demolded from the inner neck mold 52 by inserting an ejection rod 81 into the hollow article 10 to be engaged with an inner surface of the hollow article 10 and rotating the hollow article 10 together with the ejection rod 81.