An electronic-endoscope-apparatus 1 comprises an electronic-endoscope 2 and a processor device 3 that transmits and receives power and signals between the electronic-endoscope 2 and itself The electronic-endoscope 2 and the processor device 3 have connectors 13 and 14 that are connected to each other, respectively. The connectors 13 and 14 include input/output units 31 and 33 that transmit and receive power and signals, and contact parts 32 and 34 that electrically connect a ground of the electronic endoscope 2 to a ground of the processor device 3. When connection between the connectors 13 and 14 is released, contact between the contact parts 32 and 34 is released after coupling between the input/output units 31 and 33 is released and the transmission and reception of power become impossible.