1. An electronic apparatus comprising: a voice recognizer configured to recognize a user's voice; a storage configured to have previously stored instructions; a function executor configured to perform a predetermined function; and a controller configured to control the function executor to execute the function in response to the instruction in response to a user's voice corresponding to the instruction being input, and controls the function executor to execute the function in accordance with results of an external server analyzing a user's voice in response to a preset dialogue selection signal and a dialogue voice for executing the function being input by a user.