Abstract: A connector which is excellent in transmission characteristics and at the same time capable of facilitating cable-connecting operations. One contact group is comprised of a ground contact including a first contact portion and a first connection portion, a first signal contact including a second contact portion and a second connection portion, and a second signal contact including a third contact portion and a third connection portion. A plurality of the contact groups are held by a housing along a direction orthogonal to a connector fitting direction. First to third contact portions of all the contact groups are arranged on a single imaginary straight line substantially orthogonal to the connector fitting direction.