To provide an optical DVI (digital visual interface) cable which does not cause a destruction of an input output device even if there arises a potential difference between an internal power source and an external power source in a combination type of the internal power feed type and an external power feed type.

A diode 25 for reverse current prevention is installed on a first metal wire 42 to connect a transmission side interface 2 and a receiving side interface 3 and nearer a host device 50 side than an AC/DC adaptor 6 which is the external power source.