A connector for differential transmission is disclosed. The connector includes a housing made of an insulating material, the housing including a connector connection opening on its top face, multiple signal contact pairs each including first and second signal contact members, the signal contact members each including a signal terminal part, and multiple ground contact members each including ground terminal parts. The signal contact pairs and the ground contact members are disposed alternately in the housing so that the signal terminal parts of the first and second signal contact members of the signal contact pairs and the ground terminal parts of the ground contact members are provided on the side of the bottom face of the housing. The signal terminal parts of the first and second signal contact members extend in the same direction in each signal contact pair.