An endoscopic system includes: an endoscope acquiring an image of an inside of a subject； and a processing device performing image processing on the acquired image. The endoscope includes: an imaging unit outputting the image of the inside of the subject as an electrical signal； and an optical transmission unit converting the electrical signal into an optical signal and transmitting the optical signal to the processing device via an optical fiber. The processing device includes: an optical reception unit receiving the optical signal transmitted from the optical transmission unit and converts the received optical signal into an electrical signal； a curvature-detecting unit detecting a curvature of the optical fiber, and a control unit controlling at least one of characteristics of the electrical signal output from the imaging unit and characteristics of the electrical signal output from the optical transmission unit based on the detection result of the curvature-detecting unit.
