To provide an endoscope with small bending resistance difficult to be damaged or broken even in repeated uses.

This endoscope comprises a flexible insert part 2 and an operation part set on the proximal end of the insert part 2. The insert part 2 comprises lengthy members such as an image guide 31 or a light guide 32 arranged in a tube cavity formed of an outer skin 382 or the like. The light guide 32 comprises an optical fiber bundle and a protective tube 321 for protecting the optical fiber bundle. A lubricating agent 5 containing silicone oil and a solid lubricant is arranged in the protective tube 21. The solid lubricant contains at least one selected from boron nitride, ethylene tetrafluoride copolymer, and molybdenum disulfide. The solid lubricant is preferably formed of a powder having an average particle size of 0.1-15 μm.