A terminal and method of automatically executing function establishment thereof are disclosed, by which establishments of supportable services and additional functions can be supported under a user-oriented environment, by which a function establishment of the terminal can be automatically executed according to a user, and by which function establishment contents previously used by a user can be automatically applied to a terminal that is for rent or newly purchased. The present invention includes registering an establishment value used in executing a prescribed terminal function to a communication system, requesting the establishment value to the communication system from a random terminal, receiving the establishment value from the communication system to the terminal, and allowing the terminal to change a previous establishment value of the function previously stored in the terminal using the received establishment value.