PROBLEM TO BE SOLVED: To surely remove soiled matter adhering to an observation window, by increasing pressure to improve cleanability of the observation window.SOLUTION: The rigid endoscope is provided with an endoscope body which comprises an operating portion and a rigid insertion portion connected to a leading end of the operating portion. The rigid endoscope includes a fluid pipeline which supplies a cleaning fluid for cleaning the observation window formed in the leading end of the insertion portion, and a valve which is opened when pressure of the cleaning fluid supplied by the fluid line reaches certain pressure or higher.
