An endoscope system 1 includes: an image pickup device 14 configured to output a digital signal； an EEPROM 28 in which predetermined information concerning an endoscope is recorded； a signal control portion 42 capable of selectively converting data of at least one of the digital signal outputted from the image pickup device 14 and the predetermined information of the EEPROM 28 to serial data and outputting the serial data； an electro-optical conversion portion 27 configured to convert the data outputted from the signal control portion 42 to an optical signal and output the optical signal； a universal cable 5； and a data switching portion 41 switched to transfer the predetermined information from the EEPROM 28 by the signal control portion 42 and then transfer the digital signal by the signal control portion 42.
