A disclosed coaxial connector includes: an external conductor having a cylindrical shape to be screwed together with a counterpart connector including a circular opening end, the external conductor having a contact surface provided on inner periphery of the external conductor, with which the opening end comes into contact, and also having a slit formed to allow the external conductor to stretch and shrink in a longitudinal direction of the external conductor; and a center conductor provided coaxial with the external conductor, the center conductor having a length long enough to reach a substrate on which the counterpart connector is provided upright.