A charging system comprising: a vehicle configured to be chargeable by an external power supply external to the vehicle; a charging cable for supplying electric power from said external power supply to said vehicle; and a relay provided on said charging cable, said vehicle including: a rechargeable power storage device; a charging port configured so that said charging cable can be connected to the charging port; a charger configured to receive electric power supplied from said external power supply for charging said power storage device; a control unit configured to control said relay so that said relay is in an ON state while said power storage device is charged by said charger; and a communication unit configured to use said charging port and said charging cable as a communication path for communicating with a communication device external to the vehicle, characterized in that said control unit is configured to control said relay so that said relay is in an OFF state, in a case where communication with said communication device external to the vehicle by said communication unit has come to an end when charging of said power storage device by said charger comes to an end, and said control unit is configured to maintain said relay in the ON state, in a case where communication with said communication device by said communication unit is continuing when charging of said power storage device by said charger comes to an end. a vehicle configured to be chargeable by an external power supply external to the vehicle; a charging cable for supplying electric power from said external power supply to said vehicle; and a relay provided on said charging cable, said vehicle including: a rechargeable power storage device; a charging port configured so that said charging cable can be connected to the charging port; a charger configured to receive electric power supplied from said external power supply for charging said power storage device; a control unit configured to control said relay so that said relay is in an ON state while said power storage device is charged by said charger; and a communication unit configured to use said charging port and said charging cable as a communication path for communicating with a communication device external to the vehicle, a rechargeable power storage device; a charging port configured so that said charging cable can be connected to the charging port; a charger configured to receive electric power supplied from said external power supply for charging said power storage device; a control unit configured to control said relay so that said relay is in an ON state while said power storage device is charged by said charger; and a communication unit configured to use said charging port and said charging cable as a communication path for communicating with a communication device external to the vehicle, characterized in that said control unit is configured to control said relay so that said relay is in an OFF state, in a case where communication with said communication device external to the vehicle by said communication unit has come to an end when charging of said power storage device by said charger comes to an end, and said control unit is configured to maintain said relay in the ON state, in a case where communication with said communication device by said communication unit is continuing when charging of said power storage device by said charger comes to an end.