An outer conductor 70 has arm-shaped portions 74 that extend from a mating body portion 73, the arm-shaped portions 74 are of a curved shape and have front contact portions 74B-2 enabled to contact the mating body portion 73 and rear contact portions 74B-1 enabled to contact cover plate portions 76, and bringing the front contact portions 74B-2 into contact with the mating body portion 73 while bringing the rear contact portions 74B-1 into contact with the cover plate portions 76 places the counterpart outer conductor and the cover plate portions 76 in electrical communication via the mating body portion 73, front contact portions 74B-2, and rear contact portions 74B-1.