The present invention aims at providing an ion milling apparatus for emitting an ion beam to a sample to process the sample and capable of controlling the temperature of the sample with high accuracy regardless of deformation or the like of the sample being irradiated with the ion beam, and proposes an ion milling apparatus including at least one of a shield holding member for supporting a shield for shielding the sample from the ion beam while exposing a part of the sample to the ion beam; a shifting mechanism for shifting a surface of the sample stand in contact with the sample following deformation of the sample during irradiation with the ion beam, the shifting mechanism having a temperature control mechanism for controlling temperature of at least one of the shield holding member and the sample stand; and a sample holding member disposed between the shield and the sample, the sample holding member deforming following deformation of the sample during irradiation with the ion beam, for example.