To provide a connector capable of suppressing crosstalk between adjacent different pairs of signal lines on a printed circuit board, and facilitating impedance matching.

The connector includes first signal contacts 51 each including a first signal terminal portion 51d mounted on the printed circuit board, second signal contacts 52 each including a second signal terminal portion 52d mounted on the printed circuit board, first ground contacts 61 each including bifurcated ground terminal portions 61d mounded on the printed circuit board, second ground contacts each including a second ground terminal portion mounted on the printed circuit board, and a housing which holds these contacts. A first terminal portion group wherein virtual lines connect terminal portions to form a quadrangle is configured by a pair of the first and second signal terminal portions 51d and 52d and the bifurcated first ground terminal portion 61d. A second terminal portion group wherein virtual lines connect terminal portions to form a triangle is configured by a pair of the first and second signal terminal portions and the second ground terminal portion. The first and second terminal portion groups are arranged along a predetermined direction (A) in an alternating manner.