A hollow container manufacturing method comprises; an injection molding step of forming a preform having a neck portion and a barrel portion, at least a part of the barrel portion being solid, by injection molding; an intermediate product formation step of inserting a boring rod 134 from the neck portion side into the barrel portion 23 to form a space pare of at least a predetermined depth in the barrel portion, thereby converting the preform into an intermediate molded product; and a final blow molding step of blow-molding the intermediate molded product within a final blow mold to form a hollow container which is a final molded product.

A cup-shaped body having an axis of longitudinal extension and defining a mouth and a longitudinally-extended body which is closed at the opposite end from the mouth; the longitudinally-extended body has a conical or frustum-like extension with a diameter that increases progressively from the opposite end toward the mouth, the cup-shaped body having a height extension measured between the mouth and the opposite end, while the mouth has a circular shape with a diameter.

The cup-shaped body has the following features: the ratio between the height extension and diameter is between 0.35 and 1.65; and the ratio between the diameter, measured in millimeters, and the average taper (Cmedia) between the taper of the external surface of the longitudinally-extended body and the taper of the internal surface of the longitudinally-extended body, diameter/Cmedia, is between 0.5 and 1.

A method of producing a resin container includes injection-molding a resin intermediate molded body of bottomed cylindrical shape as a first injection-molding, injection-molding a resin material outside the intermediate molded body as a second injection-molding, to produce a multilayer preform in which a resin layer is layered on an outer peripheral side of the intermediate molded body, and blow-molding the preform in a state of containing residual heat from injection-molding to produce a resin container having a bottom portion thicker in wall thickness than a body portion. A portion of the inner peripheral side of the intermediate molded body, the portion reaching a bottom portion of the intermediate molded body, has a tapered region in which the wall thickness increases toward the bottom portion.