A navigation system incorporating an antenna includes a cabinet constructed of electroplated case and cover. An antenna element is integrated to the cabinet and electrically connected with the cover that is a ground of the antenna element. With this configuration, the cabinet and the antenna element can be installed in a vehicle at once and wiring of the antenna element outside the cabinet can be eliminated. Thus, installability of the navigation system is improved in comparison with known devices. Furthermore, the cover is formed such that its surface is larger than that of the antenna element. As a result, directivity of the antenna element is properly secured.