PURPOSE: To obtain a method and an apparatus enabling an analysis or an area smaller than a casting size of using primary beams without directly making the size smaller.

CONSTITUTION: A sample stage having a minimum moving amount and positioning accuracy smaller than a casting size of primary beams is used. A positional relationship whereby a part where a plurality of casting areas A, B, C and D overlap each other, almost agrees with a desired analysis area 1, is selected. An X-ray spectrum is measured in this state, so that data of the analysis area and background are extracted from the data of the spectrum.