A female connector (1) is connectable to a male connector (100) including a cylindrical male member (921). The female connector (1) includes: a tubular portion (11) having a hollow circular cylindrical shape to which the male member (921) is insertable； and a cylindrical portion (17) having a hollow circular cylindrical shape that is coaxial with the tubular portion (11) and surrounded by the tubular portion (11). When the male member (921) is inserted into the tubular portion (11), a liquid-tight seal (19) is formed between the cylindrical portion (17) and the male member (921), and the cylindrical portion (17) and the male member (921) communicate with each other.
