There is provided a repair apparatus including a gas field ion source which includes an ion generation section including a sharpened tip, a cooling unit which cools the tip, an ion beam column which forms a focused ion beam by focusing ions of a gas generated in the gas field ion source, a sample stage which moves while a sample to be irradiated with the focused ion beam is placed thereon, a sample chamber which accommodates at least the sample stage therein, and a control unit which repairs a mask or a mold for nano-imprint lithography, which is the sample, with the focused ion beam formed by the ion beam column. The gas field ion source generates nitrogen ions as the ions, and the tip is constituted by an iridium single crystal capable of generating the ions.