In order to acquire typical X-ray spectra by dividing automatically dividing contained matter and regions where the density thereof differs into groups in X-ray mapping analysis, measurement starts with the spectra database empty, a designated location within the sample is irradiated with a primary beam by the primary beam control means, the sample is irradiated with the primary beam for a fixed period of time in order to acquire a measurement spectrum, the X-ray spectrum obtained through measurement and X-ray spectra in the spectra database are compared by the X-ray comparison means, the X-ray spectrum obtained through measurement is added to the database when no matching X-ray spectra exists in the database, and measurement is repeated at a designated measurement point.