A contact probe includes a plurality of probes, each of the probes including: an conductive tube; an conductive plunger, contained in at least one end side of the tube, and having a distal end part protruding outward from the tube in an axial direction of the tube; and a coil spring, contained in the tube, and adapted to elastically urge the plunger outward. The plural probes are arranged in a first direction in a socket comprised of insulating material. A cross section of the tube in a direction perpendicular to the axial direction of the tube has a greater size in a direction different from the first direction than a size in the first direction.