An endoscope system comprises a plurality of endoscope components including at least one endoscope light source apparatus for supplying illumination light to an endoscope and at least one video signal processing unit for processing video signals provided by the endoscope, a main control unit for controlling the plurality of endoscope system components, and a main operational instruction unit connected to the main control unit and used to operate the plurality of endoscope system components. The main operational instruction unit includes a display capable of selectively displaying operational instruction input screens associated with functions possessed by the plurality of endoscope system components.