PURPOSE: To obtain a gas extractor for geothermal turbine condenser having high extraction efficiency, by driving the turbine with saturated water while driving a gas compressor by the power produced from the turbine and extracting non-condensable gas from the condenser.

CONSTITUTION: Saturated water separated by a gas/water separator 2 is fed through a conduit 17 to a hot water turbine 20 to produce power for driving a screw-type gas compressor 30 coupled through a gear 26 to the shaft of rotor 22. A conduit 35 communicating with the condenser 12 is provided at the suction port 36 of gas compressor 30 to suck non-condensable gas from condenser 12 through conduit 35 continuously and deliver through a suction port 37 to the outside under atmospheric state.