To provide a connector device capable of assuring the safety of an information processing device which is different from a video apparatus, corresponding to a currently preset connection mode.

A series circuit, consisting of a resistor 3 and a first switch 5, is provided between a line L1 connecting an input port 1 with an output port 2, and the ground. A control circuit is provided to control so as to turn on or off the first switch, when a CSYNC signal from the video apparatus or a HSYNC signal from the information processing device is inputted into the input port 1. For example, if the information processing device is connected incorrectly, when the connection mode for the video apparatus is selected, the first switch is switched from turn off to turn on, thus making the input impedance between the line L1 and the ground to be a high impedance.