Focused ion beam apparatus, and control method for focused ion beam apparatus

The focused ion beam apparatus includes: an ion source configured to generate ions; a first electrostatic lens configured to accelerate and focus the ions to form an ion beam; a beam booster electrode configured to accelerate the ion beam to a higher level; one or a plurality of electrodes, which are placed in the beam booster electrode, and are configured to electrostatically deflect the ion beam; a second electrostatic lens, which is provided between the one or plurality of electrodes and a sample table, and is configured to focus the ion beam applied with a voltage; and a processing unit configured to obtain a measurement condition, and set at least one of voltages to be applied to the one or plurality of electrodes or a voltage to be applied to each of the first electrostatic lens and the second electrostatic lens, based on the obtained measurement condition.