A navigation device that is mounted in a movable body of the present invention includes a first storing portion that stores a first navigation data; an acquiring portion that acquires a second navigation data from an external second storing portion; a movable body location detecting portion that detects the location of the movable body; a navigation operation executing portion that executes a predetermined navigation operation based on the location of the movable body that is detected by the movable body location detecting portion, and the first navigation data; and an updating portion that updates the first navigation data with the second navigation data. The updating portion stops the execution of the navigation operation by the navigation operation executing portion, and executes a first updating process that updates a portion of the first navigation data corresponding to a first area that includes the vicinity of the location of the movable body; and a second updating process that updates a portion corresponding to a second area of the first navigation data other than the first area in parallel with the navigation operation by the navigation operation executing portion, after this first updating process is completed.