An endoscope gas feed system includes a fluid curtain nozzle for blowing a fluid curtain-forming gas toward an observation window provided on a distal end surface of the insertion part of an endoscope, the distal end surface including at least the observation window and an opening for spraying a constant-pressure feed gas, and the fluid curtain nozzle is provided on an opposite side of the opening with respect to the observation window, a gas/water feed nozzle for cleaning the observation window, the gas/water feed nozzle being provided on the distal end surface, a constant-pressure gas feed unit for supplying the constant-pressure feed gas, so as to spray the constant-pressure feed gas from the opening, and a fluid curtain-forming gas feed unit for supplying a gas, so as to blow the fluid curtain-forming gas from the fluid curtain nozzle.
