To provide a charged particle beam analyzer enabling an efficient and high-sensitivity analysis of a microscopic light element contained in a heavy metal sample, the charged particle beam analyzer equipped with a WDX spectrometer includes a storage unit 126 having stored therein a correlation database between average atomic numbers and WDX background intensity values obtained with use of a plurality of standard samples and a WDX background processing means 146 including a means 147 for calculating an average atomic number for a sample 129 and a means for eliminating a WDX background intensity value derived from the average atomic number for the sample 129 and the correlation database from a WDX spectrum for the sample 129.
