A charging system comprising: a first control device provided in a vehicle for controlling external charging of a power storage device mounted on said vehicle by a power supply outside of the vehicle, wherein the first control device is further configured to determine a reservation input in the first control device, the reservation indicating an instruction made in advance for informing about a start time and/or an end time of said external charging; and a second control device provided in a charging apparatus outside of said vehicle for controlling the external charging, wherein in advance means before a communication between the first and second control devices (170, 406) becomes possible, characterized in that the second control device is further configured to determine a reservation input in the second control device, the reservation indicating an instruction made in advance for informing about a start time and/or an end time of said external charging, wherein, when a reservation for said external charging has been made in both said first control device and said second control device by a request of a user, said second control device is configured to select to execute said external charging in accordance with the reservation input in said second control device, when the reservation for said external charging has been made in both said first control device and said second control device, but the reservation input in said first control device has been made at a request based on a state of said vehicle which is different from the request by the user, said second control device is configured to select to execute said external charging in accordance with the reservation input in said first control device. a first control device provided in a vehicle for controlling external charging of a power storage device mounted on said vehicle by a power supply outside of the vehicle, wherein the first control device is further configured to determine a reservation input in the first control device, the reservation indicating an instruction made in advance for informing about a start time and/or an end time of said external charging; and a second control device provided in a charging apparatus outside of said vehicle for controlling the external charging, wherein in advance means before a communication between the first and second control devices (170, 406) becomes possible, characterized in that the second control device is further configured to determine a reservation input in the second control device, the reservation indicating an instruction made in advance for informing about a start time and/or an end time of said external charging, wherein, when a reservation for said external charging has been made in both said first control device and said second control device by a request of a user, said second control device is configured to select to execute said external charging in accordance with the reservation input in said second control device, when the reservation for said external charging has been made in both said first control device and said second control device, but the reservation input in said first control device has been made at a request based on a state of said vehicle which is different from the request by the user, said second control device is configured to select to execute said external charging in accordance with the reservation input in said first control device. when a reservation for said external charging has been made in both said first control device and said second control device by a request of a user, said second control device is configured to select to execute said external charging in accordance with the reservation input in said second control device, when the reservation for said external charging has been made in both said first control device and said second control device, but the reservation input in said first control device has been made at a request based on a state of said vehicle which is different from the request by the user, said second control device is configured to select to execute said external charging in accordance with the reservation input in said first control device.