In order to automatically distinguish a type of cable connected to a display apparatus, and transmit appropriate specification information to a host, when a host 10 and a display apparatus 100 are connected via a DVI-D to DVI-D cable 14 for digital signal, a DDC 5V from the host is applied to an emitter of a detection transistor 19, and a lower voltage due to a resistor 17 is applied to its base so that the detection transistor turns on. A collector voltage thus becomes an H level so that a multiplexer 21 is switched to the side of a non-volatile memory 23 in which a digital EDID is stored. When they are connected via a D-Sub to DVI-I conversion cable 15 for analog signal, a DDC 5V terminal and an HPD terminal of the cable are short circuited, so the detection transistor turns off, the collector voltage becomes an L, and the multiplexer is switched to the non-volatile memory side in which an analog EDID is stored.