An endoscope for inspection of an observation cavity, in particular of an observation cavity in which a hot medium and/or infrared radiation is present, has a shaft in which an optical system is arranged. The shaft has an inner shaft and an outer shaft surrounding the latter at a distance, the optical system being arranged in the inner shaft. The shaft is configured in the region of its distal end in such a way that it is substantially opaque to electromagnetic radiation in the infrared spectral range.