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 each including a signal terminal portion, second signal contacts each including a signal terminal portion, first ground contacts each including bifurcated terminal portions, second ground contacts each including a terminal portion, and a housing which holds these contacts. Each signal terminal portion, bifurcated terminal portion and terminal portion are mounted on a printed circuit board. Virtual lines connecting terminal portions forming each first terminal portion group form a quadrangle. Virtual lines connecting terminal portions forming each second terminal portion group form a triangle. The first and second terminal portion groups are arranged along a predetermined direction in an alternating manner.