An endoscope system, comprising: a mantle tube into which an insertion part of an endoscope is inserted a fluid flow channel which is formed of a space between an outer surface of the endoscope inserted into the mantle tube and an inner surface of the mantle tube a sealing member which seals the fluid flow channel and a pipe line which is formed inside of the insertion part so as to communicate between the fluid flow channel and a nozzle formed on a leading end surface of the insertion part, and supply a fluid from the fluid flow channel to the nozzle.
