The present invention discloses a repair apparatus which causes less damage to a sample and is capable of repairing a minute region of a mask or the like stably and efficiently over a long period of time. The repair apparatus (10) at least includes: a gas field ion source including a sharpened tip; a cooling unit which cools the tip; an ion beam column (11) which forms a focused ion beam by focusing ions of a gas generated in the gas field ion source; a sample stage (15) which moves while a sample to be irradiated with the focused ion beam formed through the ion beam column (11) is placed thereon; a sample chamber (13) which accommodates the sample stage (15) therein; and a control unit (20) which repairs a mask (14) or a mold for nano-imprint lithography, which is the sample, with the focused ion beam. The gas field ion source takes nitrogen as the ions, and has the tip constituted by an iridium single crystal having a single peak capable of generating the ions.