Charged particle beam irradiation apparatus and control method

A charged particle beam irradiation apparatus, comprising:

• a focused ion beam column configured to irradiate, with a focused ion beam, a multilayered sample in which a plurality of layers having one of different substances and different structures from one another are stacked in a predetermined stacking direction as observation target layers to be observed;
• an electron beam column configured to irradiate the multilayered sample with an electron beam;
• an electron detector configured to detect one of secondary electrons and reflection electrons generated from the multilayered sample;
• and
• a control unit configured to repeatedly perform exposure control in which the focused ion beam column is controlled to expose a cross section of the multilayered sample toward the predetermined stacking direction with the focused ion beam,
• the control unit being configured to perform, every time exposure of one of the observation target layers at a cross section of the multilayered sample is detected in a process of repeatedly performing the exposure control, observation control in which the electron beam column is controlled to radiate the electron beam, and observation image of the cross section of the multilayered sample is formed.