PROBLEM TO BE SOLVED: To provide a rigid endoscope having an observation window which can be washed and dried by simple constitution, in a short time.SOLUTION: The rigid endoscope includes a capsule housing part 52 provided in an operation part 20 without providing a water sending tank at the outside, and houses a water capsule 78 in the capsule housing part 52 in a freely detachable manner. The washing water 76 to be filled in the water capsule 78 is required only by the amount to be used in one washing operation, and in the next operation, the water capsule 78 is replaced with a new water capsule 78. The rigid endoscope is only equipped with a COcylinder at the outside, and also equipped with a changeover valve 74 for selectively supplying the COgas from the COcylinder to gas piping 86 or the capsule housing part 52. The rigid endoscope uses no water piping and gas piping, and they are independently provided. By this constitution, drainage in drying the washing water on the observation window or illumination window is enhanced.
