An electronic device is provided. The electronic device includes a substrate and a joint. The substrate includes a first surface and a second surface, wherein a substrate signal contact, two ground contacts and two positioning openings are formed on the substrate, and the positioning openings are respectively formed on the ground contact and pass through the substrate. The joint includes a connection port, a joint signal contact and two ground structure, wherein the connection port is electrically connected to the joint signal contact, the joint signal contact is connected to the substrate signal contact, and the joint signal contact is located between the two ground structures, and the ground structures are respectively inserted into the positioning openings to be electrically connected to the ground contacts.