A coaxial connector includes a base surface; a coaxial structure where a dielectric is between a central conductor and an outer conductor; and a protrusion protruding from the base surface. The central conductor includes a contact portion protruding from the base surface. In response to a substrate being inserted toward the base surface between the contact portion and the protrusion, the contact portion comes into contact with a conductor pattern formed on a surface of the substrate. The outer conductor includes a protruding conductor protruding from the base surface and not in contact with the substrate inserted between the contact portion and the protrusion.