Provided is an electronic apparatus (EA) and a user authentication method thereof both can prevent information leakage and disadvantages caused by an unauthorized access to the EA. The EA is configured to store a combination of a recognizing-code and a key-code correlated therewith, the combination being in relationship with each of plural users, and to give a user an exclusive authority for executing a specific process if an inputted combination of a recognizing-code and a key-code=the stored combination of the recognizing-code and the key-code. In case of a request for accepting the specific process, if the inputted combination of the recognizing-code and the key-code is≠the stored combination of the recognizing-code and the key-code, the EA notifies, without executing the specific process, initiating a receipt of instructing the specific process to user of the inputted combination.