This is an endoscope apparatus which has an endoscope which picks up an image of a sample using a solid state image pickup element and outputs an image pickup signal, and a processor which processes the above-mentioned image pickup signal, generates HDTV and SDTV serial digital video signals, switches one side of those selectively, and performs a serial output, in which the serial digital video signal switched selectively by the above-mentioned processor is output through a first connector, the above-mentioned processor is equipped with a discrimination signal generating section which is linked with selection switching of the above-mentioned HDTV or SDTV serial digital video signal to generate an HDTV/SDTV discrimination signal which can discriminate the above-mentioned HDTV or SDTV serial digital video signal, and the discrimination signal is output through a second connector different from the above-mentioned first connector.