Charged particle beam alignment method and charged particle beam apparatus

A charged particle beam apparatus comprising:

• a charged particle source;
• an optical element for adjusting a charged particle beam emitted by the charged particle source;
• an alignment deflector for aligning the axis of the charged particle beam with respect to the optical element;
• a control device for calculating alignment correction value of the alignment deflector based on an image movement amount detected when the optical element is varied and a calculation formula indicating that a value obtained based on a calculation of a proportion of a change amount of the image movement amounts before and after supplying a predetermined signal to the alignment deflector, with respect to the predetermined signal is equal to a value obtained based on a calculation of a proportion of the image movement amounts before supplying a predetermined signal to the alignment deflector, with respect to the alignment correction value;
• and
• selecting means for selecting whether or not to calculate a parameter indicating a relative sensitivity ratio of x component and y component of the alignment correction value of the alignment deflector,
• wherein the control device calculates the parameter based on images before and after supplying the predetermined signal to the alignment deflector to calculate the x and y components of the alignment correction value based on the calculated parameter and the calculation formula, when calculating the parameter is selected by the selecting means,
• wherein the control device calculates the x and y components of the alignment correction value based on the calculation formula and the parameter which is stored in a memory in advance, when calculating the parameter is not selected by the selecting means.