1. An instruction executing method performed by an information terminal in which an instruction is executed by recognizing coordinates of a selected item or a voice of a user when one of a plurality of items displayed on a touch screen is selected, the method comprising the steps of: (a) recognizing the voice of the user input when one of the items is selected on the touch screen; (b) upon recognizing a voice corresponding to one of a plurality of sub-instructions corresponding to coordinates of the item selected in step (a), executing a corresponding sub-instruction; and (c) upon recognizing no voice corresponding to any one of the sub-instructions, displaying the plurality of sub-instructions on the touch screen.