The endoscope light source apparatus of this invention can be selectively connected with an endoscope having a light guide means which can transmit an illuminating light for an object and an endoscope having a light source which can illuminate an object. The endoscope connected to the endoscope light source apparatus is discriminated by a scope discriminating circuit outputting a signal which can control a light guide light source and a power source which can feed an electric power to the light source provided in the endoscope.
