A vehicle management server, configured to manage information on a control device mounted on a vehicle, and information on a plurality of information terminals (130, 300) connectable with the control device, the vehicle management server comprising: an acquisition unit configured to acquire,as information indicating a positional relationship between the information terminals (130, 300) and the control device, location information regarding the vehicle and location information regarding all the information terminals that are registered in advance in a storage unit of the vehicle management server in association with the vehicle; a determination unit configured - to derive, based on a plurality of pieces of location information acquired by the acquisition unit, distances between the vehicle and the information terminals, respectively; - to determine, based on the derived distances, whether or not there is an information terminal that is distanced by a set threshold or more from the vehicle, said set threshold being based on a form of usage of the vehicle; and - if so, to determine the information terminal distanced by the set threshold or more from the vehicle as a first information terminal that is out of the setting range; and a notification unit configured, - when there is such a first information terminal out of the setting range, to transmit a first message to a display device of at least one second information terminal different from the first information terminal among the information terminals (130, 300), said first message indicating that there is a registered information terminal other than said at least one second information terminal, and - when there is no first information terminal out of the setting range, not to transmit such a first message. an acquisition unit configured to acquire,as information indicating a positional relationship between the information terminals (130, 300) and the control device, location information regarding the vehicle and location information regarding all the information terminals that are registered in advance in a storage unit of the vehicle management server in association with the vehicle; a determination unit configured - to derive, based on a plurality of pieces of location information acquired by the acquisition unit, distances between the vehicle and the information terminals, respectively; - to determine, based on the derived distances, whether or not there is an information terminal that is distanced by a set threshold or more from the vehicle, said set threshold being based on a form of usage of the vehicle; and - if so, to determine the information terminal distanced by the set threshold or more from the vehicle as a first information terminal that is out of the setting range; and - to derive, based on a plurality of pieces of location information acquired by the acquisition unit, distances between the vehicle and the information terminals, respectively; - to determine, based on the derived distances, whether or not there is an information terminal that is distanced by a set threshold or more from the vehicle, said set threshold being based on a form of usage of the vehicle; and - if so, to determine the information terminal distanced by the set threshold or more from the vehicle as a first information terminal that is out of the setting range; and a notification unit configured, - when there is such a first information terminal out of the setting range, to transmit a first message to a display device of at least one second information terminal different from the first information terminal among the information terminals (130, 300), said first message indicating that there is a registered information terminal other than said at least one second information terminal, and - when there is no first information terminal out of the setting range, not to transmit such a first message. - when there is such a first information terminal out of the setting range, to transmit a first message to a display device of at least one second information terminal different from the first information terminal among the information terminals (130, 300), said first message indicating that there is a registered information terminal other than said at least one second information terminal, and - when there is no first information terminal out of the setting range, not to transmit such a first message.