An endoscope system (2) in which an imaging signal is transmitted in serial from an imaging device (42) of an endoscope to an external control device (a processor device (11)), disturbance of an image can be reduced even if data corruption occurs due to noise or the like during transmission of the imaging signal, and the external control device (11) for the endoscope are provided. In the processor device (11) connected to the endoscope, the imaging signal transmitted in serial from an imaging chip of the endoscope is converted by an S/P converter (81) to parallel data, and is then decoded by an 8B10B decoder (82). When data corruption occurs due to noise or the like during transmission of the imaging signal and normal pixel data cannot be obtained due to decode error at an 8B10B decoder (82), that pixel data is interpolated with pixel data of a peripheral part in an inner memory (112) of an image processing circuit (83).
