1. A method for operating a mobile terminal, the method comprising: presenting help information prompting a voice input requesting an execution of a search function for functions of the mobile terminal; displaying a list of menu items corresponding to a plurality of applications of the mobile terminal in response to a receipt of the voice input requesting the execution of the search function for the functions of the mobile terminal; displaying detailed information related to a menu item when the menu item is selected from the list of menu items based on a user input; and executing one of the plurality of applications corresponding to the menu item in response to a receipt of a voice command based on at least a part of the detailed information.