Abstract: A charged particle beam apparatus for processing a tip end portion of a sample into a needle shape, includes an ion beam irradiation unit that irradiates the tip end portion with ion beams, an electron beam irradiation unit that irradiates the tip end portion with electron beams, a secondary electron detection unit that detects secondary electrons generated at the tip end portion by the irradiation with the electron beams, and an EBSD detection unit that detects diffracted electrons generated at the tip end portion by the irradiation with the electron beams.