A junction box has a PCB, on which fuses, relays, and a control and communication unit are mounted. The PCB is provided with upper and lower surfaces, on which a first connector and a second connector are respectively positioned. Further, the junction box includes a cover covering the PCB in such a way as to expose the fuses, the first connector, and the second connector. Since the fuses, the relays, and the control and communication unit are mounted on a single board, the junction box reduces manufacturing costs of the board, reduces size and weight of the board, and effectively performs communication with external electronic modules.