Provided is a device including a display, an audio inputter, and a controller. The display displays at least one screen page of an application that is being executed. The audio inputter receives a voice command of a user. The controller performs an operation corresponding to the voice command by using screen page transition information for transition between application screen pages corresponding to the voice command, which is obtained from information about user interface (UI) elements included in the application screen pages of the application. Each of the UI elements performs a predetermined function when selected by the user.