Optical system adjustment method for multi charged particle beam apparatus and computer readable recording medium

A non-transitory computer readable recording medium storing a program causing a computer to execute a process for adjusting an optical system of a multi charged particle beam apparatus that irradiates a substrate placed on a stage with a multi charged particle beam through an illumination optical system including a plurality of components, and an objective lens successively, the process comprising the steps of:

• measuring positional deviation amounts of a plurality of individual beams included in the multi charged particle beam at two or more different heights in an optical axis direction of a measurement surface or an imaging position of the multi charged particle beam;
• calculating a normalized position difference based on the two or more heights and the positional deviation amounts, the normalized position difference being an illumination system aberration equivalent amount of the illumination optical system;
• and
• adjusting a set value for at least one of the plurality of components using a value of the normalized position difference.