1. A portable terminal comprising: a memory unit configured to store an Earth's magnetic field component corresponding to a predetermined zone for controlling a function of the portable terminal, and information of function to be executed at the predetermined zone; and a controller coupled to the memory unit, the controller configured to: control a sensor to acquire an Earth's magnetic field component corresponding to a current location of the portable terminal, determine whether the portable terminal is located within the predetermined zone by comparing the acquired Earth's magnetic field component and the stored Earth's magnetic field component, and if the portable terminal is located within the predetermined zone, execute a function corresponding to the predetermined zone in which the portable terminal is located.