A method for displaying an optimal path of a moving object in a navigation device, the method comprising the steps of: setting (S32, S62) an optimal path according to a destination of a moving object, the optimal path comprising a first optimal path portion and a second optimal path portion; detecting (S34, S64) a current position of the moving object traveling along the optimal path; displaying, in association with the current position of the moving object, the first optimal path portion in a current traveling area, which is an area within a first predetermined scope from the current position of the moving object; determining (S40, S72) whether a traveling-stopped time of the moving object is greater than or equal to a predetermined time, when the moving object stops on the first optimal path portion; and characterised by the further steps of: in response to determining that the traveling-stopped time of the moving object is greater than or equal to the predetermined time, displaying (S42, S74) a display screen divided into two sub-screens comprising a first sub-screen displaying the first optimal path portion and a second sub-screen displaying at least part of the first optimal path portion and the second optimal path portion in a forward area as a forward path preview, wherein the forward area is an area through which the moving object should travel after traveling through the current traveling area and extending within a second predetermined scope which is beyond the first predetermined scope; wherein the second optimal path portion is subsequent to the first optimal path portion. setting (S32, S62) an optimal path according to a destination of a moving object, the optimal path comprising a first optimal path portion and a second optimal path portion; detecting (S34, S64) a current position of the moving object traveling along the optimal path; displaying, in association with the current position of the moving object, the first optimal path portion in a current traveling area, which is an area within a first predetermined scope from the current position of the moving object; determining (S40, S72) whether a traveling-stopped time of the moving object is greater than or equal to a predetermined time, when the moving object stops on the first optimal path portion; and characterised by the further steps of: in response to determining that the traveling-stopped time of the moving object is greater than or equal to the predetermined time, displaying (S42, S74) a display screen divided into two sub-screens comprising a first sub-screen displaying the first optimal path portion and a second sub-screen displaying at least part of the first optimal path portion and the second optimal path portion in a forward area as a forward path preview, wherein the forward area is an area through which the moving object should travel after traveling through the current traveling area and extending within a second predetermined scope which is beyond the first predetermined scope; wherein the second optimal path portion is subsequent to the first optimal path portion. in response to determining that the traveling-stopped time of the moving object is greater than or equal to the predetermined time, displaying (S42, S74) a display screen divided into two sub-screens comprising a first sub-screen displaying the first optimal path portion and a second sub-screen displaying at least part of the first optimal path portion and the second optimal path portion in a forward area as a forward path preview, wherein the forward area is an area through which the moving object should travel after traveling through the current traveling area and extending within a second predetermined scope which is beyond the first predetermined scope; wherein the second optimal path portion is subsequent to the first optimal path portion.