An endoscope system for use in an endoscopic procedure including a plurality of endoscopes each having an insertion section to be inserted into a cavity under inspection and an operation section to which the insertion section is connected, and a plurality of disposable protection covers each having an insertion section cover for covering said insertion section of the endoscope and an operation section cover for covering said operation section of the endoscope. The operation section of the endoscope is provided with angle knobs for bending a distal end of the insertion section into a desired direction and said angle knobs are detachably secured to a shaft. In said operation section cover, there is formed an aperture through which said shaft is protruded from the operation section cover. All the angle knobs and shafts of all the endoscopes are constructed such that all the angle knobs can be detachably secured to any of the shafts.