A coaxial cable connector receptacle comprises a cylindrical shield casing made of a metallic plate and having openings at both ends, and an inner casing made of an insulating material and housed inside the shield casing and having apertures at both ends corresponding to the openings of the shield casing. The inner casing is formed of a protruding portion at the side surface thereof, the protruding portion being formed of a groove communicating with the inside of the inner casing and receiving a contact of an external circuit. A contact member having a first and second contact is provided inside the inner casing and the first contact is positioned for receiving a center conductor of a coaxial cable at the position opposing one aperture of the inner casing, while the second contact is formed at the position opposing the groove of the protruding portion in the direction orthogonal to the longitudinal direction for receiving a contact of the external circuit. The center conductor of the coaxial cable is placed in contact with the first contact of the contact member through the opening of the shield casing and the aperture of the inner casing, while the contact from the external circuit is placed in contact with the second contact of the contact member through the groove of the protruding portion.