An electronic device according to an example embodiment includes: a substrate; and a connector including a plurality of terminals disposed on a first area of the substrate, wherein the substrate includes: a first layer including signal lines connected to the plurality of terminals and a dielectric material disposed between the signal lines; a second layer disposed on the first layer, and including a first ground electrically connected with the connector and a second ground physically isolated from the first ground; a third conductive layer disposed on the second layer, and electrically connected with the second ground; and a fourth layer having a nonconductive material disposed on an area corresponding to the first area between the second layer and the third conductive layer.