Method for manufacturing liquid container

A liquid-filled container manufacturing method comprising:

• the air discharge step of discharging air from an inside of a preform, by supplying a liquid at a level of pressure that does not cause stretching of the preform to the inside of the preform through an intra-tube channel formed between an inner peripheral surface of a spare supply tube extending through a blow nozzle and an outer peripheral surface of a spare supply rod provided radially inward thereof;
• and
• the liquid blow molding step of molding the preform into a container with a shape conforming to an inner surface of a mold, by stretching the preform downward using the spare supply rod, and supplying a pressurized liquid to the inside of the preform through an intra-nozzle channel formed between an inner peripheral surface of the blow nozzle and the outer peripheral surface of the spare supply rod, with the spare supply tube being raised so that a lower end of the spare supply tube is positioned above the inner peripheral surface of the blow nozzle.