A terminal comprising: an earphone connection interface in which at least two terminals for detecting an electrical change according to a contact state are disposed; and a controller for performing a function support according to an earphone device connection or a function support according to non-connection of the earphone device by detecting a signal change of the two terminals of the earphone connection interface, wherein the earphone connection interface comprises: a terminal microphone terminal protruded from an inner wall of a groove for contacting with an earphone plug; a terminal ground terminal for contacting with an earphone ground terminal of the earphone plug; a terminal right terminal for contacting with an earphone right terminal of the earphone plug; a terminal left terminal for contacting with an earphone left terminal of the earphone plug; an earphone detection terminal for contacting with an earphone left terminal of the earphone plug; a first pull-up resistor contacted to the earphone detection terminal and a pull-up voltage provided to the earphone detection terminal through the first pull-up resistor; a first comparator configured to use the earphone detection terminal as a first input voltage and a reference voltage as a second input voltage; and a microphone support circuit comprising a second pull-up resistor connected to the terminal microphone terminal and a pull-up voltage provided to the terminal microphone terminal through the second pull-up resistor. an earphone connection interface in which at least two terminals for detecting an electrical change according to a contact state are disposed; and a controller for performing a function support according to an earphone device connection or a function support according to non-connection of the earphone device by detecting a signal change of the two terminals of the earphone connection interface, wherein the earphone connection interface comprises: a terminal microphone terminal protruded from an inner wall of a groove for contacting with an earphone plug; a terminal ground terminal for contacting with an earphone ground terminal of the earphone plug; a terminal right terminal for contacting with an earphone right terminal of the earphone plug; a terminal left terminal for contacting with an earphone left terminal of the earphone plug; an earphone detection terminal for contacting with an earphone left terminal of the earphone plug; a first pull-up resistor contacted to the earphone detection terminal and a pull-up voltage provided to the earphone detection terminal through the first pull-up resistor; a first comparator configured to use the earphone detection terminal as a first input voltage and a reference voltage as a second input voltage; and a microphone support circuit comprising a second pull-up resistor connected to the terminal microphone terminal and a pull-up voltage provided to the terminal microphone terminal through the second pull-up resistor. a terminal microphone terminal protruded from an inner wall of a groove for contacting with an earphone plug; a terminal ground terminal for contacting with an earphone ground terminal of the earphone plug; a terminal right terminal for contacting with an earphone right terminal of the earphone plug; a terminal left terminal for contacting with an earphone left terminal of the earphone plug; an earphone detection terminal for contacting with an earphone left terminal of the earphone plug; a first pull-up resistor contacted to the earphone detection terminal and a pull-up voltage provided to the earphone detection terminal through the first pull-up resistor; a first comparator configured to use the earphone detection terminal as a first input voltage and a reference voltage as a second input voltage; and a microphone support circuit comprising a second pull-up resistor connected to the terminal microphone terminal and a pull-up voltage provided to the terminal microphone terminal through the second pull-up resistor.