A mobile device and method for performing a black box function are provided. Each of a plurality of connection ports of the mobile device are electrically connected to an external entity. When a voltage exceeding a given critical value is applied through the connection port, a detection history recording unit of the mobile device not only checks detection time information, but also checks terminal ID information about the connection port. Then the detection history recording unit records the terminal ID information and the detection time information. Therefore, when any trouble or fault occurs in the mobile device, it is possible to easily find out the cause of such trouble or fault though data recorded in the detection history recording unit.