A charged particle beam apparatus includes: a movement mechanism; a particle source; an optical element; a detector; and a control mechanism, in which the control mechanism acquires a diffraction pattern including a plurality of Kikuchi lines, calculates a crystal zone axis of the sample by performing analysis based on a plurality of intersections at which two Kikuchi lines included in the diffraction pattern intersect with each other, calculates an inclination angle of the sample based on the crystal zone axis and an irradiation direction of the charged particle beam, and controls the moving mechanism based on the inclination angle.