An endoscope system capable of avoiding generation of electromagnetic noise without affecting an image to be observed and an operating method thereof are provided. The endoscope system (10) includes at least one of a processor device (16) detachably attached to the endoscope (12) and a light source device (14) detachably attached to the endoscope (12). I have. When the endoscope (12) is attached to the processor device (16) or the light source device (14), the processor device (16) or the light source device (14) requests the digital image signal to start executing the encoding process. A request sequence for transmitting a request signal to the endoscope (12) is performed.
