Connector

A connector that can be connected to a first container and a second container to transfer a liquid between the first container and the second container, the connector comprising:

• a connector main body provided with a tubular portion and a stopcock fitted in the tubular portion so as to be rotatable around an axis of the tubular portion, one end of the tubular portion being sealed with the stopcock fitted in the tubular portion, an open portion being formed at the other end of the tubular portion, a first hole, a second hole, a third hole, and a fourth hole being formed in the connector main body;
• a first connecting portion that is engageable with the first container;
• a second connecting portion that is engageable with the second container;
• a first flow channel formed in the stopcock that passes through the stopcock in a radial direction, and
• a second flow channel formed in the stopcock that brings an opening formed on the open portion side into communication with an opening formed in a side face of the stopcock,
• wherein the second connecting portion is integrally provided with an engagement portion that is engageable with the second container and a needle-like portion for piercing into the second container, and
• wherein the connector is configured to switch between a first setting that brings the first hole into communication with the second flow channel in the stopcock and brings the third hole into communication with the fourth hole via the first flow channel and a second setting that brings the second hole into communication with the second flow channel in the stopcock and brings the third hole into communication with the fourth hole via the first flow channel by rotating the stopcock.