COMPOSITE CHARGED PARTICLE BEAM APPARATUS AND CONTROL METHOD THEREOF

Disclosed is a composite charged particle beam apparatus including: an ion supply unit supplying an ion beam; an acceleration voltage application unit applying an acceleration voltage to the ion beam supplied by the ion supply unit to accelerate the ion beam; a first focusing unit focusing the ion beam; a beam booster voltage application unit applying a beam booster voltage to the ion beam; a second focusing unit focusing the ion beam to irradiate a sample; an electron beam emission unit emitting an electron beam to irradiate the sample; and a controller setting a value of the beam booster voltage that the beam booster voltage application unit applies to the ion beam, based on a value of the acceleration voltage applied to the ion beam by the acceleration voltage application unit and of a set value predetermined according to a focal distance of the focused ion beam.