An endoscope system includes an endoscope, having a tip device for entry in a body cavity, and a viewing window portion formed in the tip device. A sleeve-shaped condition checking device is disposed on a distal side in an axial direction, for resiliently deforming in a transverse direction crosswise to the axial direction when pushed on an inner wall of the body cavity, to enter a viewing area of the viewing window portion. Furthermore, a propulsion assembly constitutes the condition checking device, and exerts force of propulsion to the tip device, for assistance to entry in the body cavity. The condition checking device includes a resilient end ring, disposed distally of a support sleeve, covered by a propulsion assembly, and having a tapered wall of which a diameter decreases in the axial direction from the support sleeve.
