An electrical connector contains a first contact group arranged on a first contact plane, a second contact group arranged on a second contact plane and a ground plate located on a ground plane. The ground plate is located between horizontally extending portions of the contacts of the first contact group and horizontally extending portions, downwardly extending portions and terminal portions of the contacts of the second contact group in addition to between contacting portions and the horizontally extending portions of the contacts of the first contact group and contacting portions and the horizontally extending portions of the contacts of the second contact group.