Provided is a connector that can improve opening properties when connecting a male connector. The connector is provided with: a housing having a duct through which a liquid passes and a male connector connection section having an approximately circular tube hole interconnecting with the duct； and a valve body that is formed from an elastic material and that occludes the male connector connection section of the housing. The valve body has: a top surface that is formed in a cylindrical shape and that is exposed from the male connector connection section； a bottom surface at the reverse side from the top surface； a slit opening to at least the top surface or bottom surface； and a thick section provided to both sides in the lengthwise direction of the slit at the bottom surface. The thick section is formed at a region encircled by the outer edge of the bottom surface and two lines intersecting the lengthwise direction of the slit.
