A connector includes an elastic valve body that includes a top face on which a slit is formed and a bottom face opposite the top face; and a holding section that is in contact with the top face and the bottom face of the elastic valve body and holds the elastic valve body. The holding section surrounds the slit, and the elastic valve body includes a peripheral section that is positioned outward of a portion of the elastic valve body that is held by the holding section when the elastic valve body is viewed from the top face side. The elastic valve body and the holding section are configured such that a volume of the peripheral section in a state in which the elastic valve body is held by the holding section is larger than a volume of the peripheral section in a state in which the elastic valve body is not held by the holding section.