The present invention relates to a method for maintaining various application installed in an image display device, and more particularly, to a method for operating an image display device, the method allowing a user to more conveniently select and execute applications in configuring selection menus of the applications, and to an image display device using the method. The method comprises: searching for applications which can be used on an image display device; displaying a first application list including selected menu items of the selected applications; and displaying one or more application key screens from among the applications which are included in the first application list. Accordingly, the user of the image display device can be provided, from the image display device, with application menus, which include menu items for running the applications that can be used on the image display device.