Residual gas volume measuring device, residual gas volume measuring method, and puncture member

A residual gas volume measuring device for measuring the volume of residual gas in a container, comprising:

• a puncture member having a first and a second communication path formed therein and connecting a penetrating portion and a coupling portion thereof together, the penetrating portion being located inside the container and the coupling portion being located outside the container when the puncture member is in a penetrating position when an end of the puncture member penetrates into the container, wherein the puncture member comprises a hollow needle and both the first communication path and the second communication path are formed within the hollow needle;
• an injection section coupled to the first communication path at the coupling portion and configured to inject a liquid into the container;
• a discharging section coupled to the second communication path at the coupling portion and configured to discharge the residual gas purged by the liquid injected by the injection section;
• and
• a measurement section configured to measure the volume of the residual gas discharged by the discharging section.