A control system of a charged particle beam apparatus obtains a first coefficient by performing multiple resolution analysis based on wavelet transform or discrete wavelet transform on at least a part of an image or a signal acquired by the charged particle beam apparatus. The control system obtains a second coefficient by performing, on at least a part of the first coefficient or an absolute value of the first coefficient, any one of calculation of a maximum value, calculation of a numerical value corresponding to a specified order in an order related to a magnitude, fitting to a histogram, calculation of an average value, and calculation of a total sum.