An endoscope system includes an image pickup device 14 that picks up an image of an inside of a subject, and outputs two or more digital signals, an electro-optical conversion section 27 that converts the two or more digital signals outputted from the image pickup device 14 into optical signals, and outputs the optical signals, an optical transmitting section 5a that includes two or more optical transmitting members, and is adapted to transmit, in parallel, by the two or more optical transmitting members, two or more optical signals outputted from the electro-optical conversion section 27, and an output selection section 26 that is provided between the image pickup device 14 and the electro-optical conversion section 27, and is capable of combining, and outputting to one optical transmitting member, the two or more digital signals that are supplied to the two or more optical transmitting members, based on a transmission state of data optically transmitted by the optical transmitting section 5a.
