An ultra precise polishing method includes controlling an irradiation time of a surface position of an object to be processed irradiated by a gas cluster ion beam. A profile is created and polished on the surface of the object to be processed by controlling irradiation of the gas cluster ion beam. An ultra precise polishing apparatus includes an irradiating device for irradiating a surface of an object to be processed by a gas cluster ion beam. A positioning device is provided for changing a surface position of the object to be processed, which is irradiated by the gas cluster ion beam by moving the irradiating device and the object to be processed relative to each other. A control device is provided for controlling the irradiation time of a surface position of the object to be processed irradiated by the gas cluster ion beam.