An electron microscope having an electron beam optical system provided with an electron source and a lens for focusing an electron beam, an optical system controller for controlling the electron beam optical system, a specimen stage on which a specimen is to be placed, an electron detector for detecting electrons emitted from the specimen by irradiating the specimen with the electron beam, an X-ray detector for detecting X rays radiated from the specimen, and a processor for processing signals from both the detectors, and performing image formation and elemental analysis of the specimens, said electron microscope comprising:
- means for detecting the count-number of X rays per unit time by detecting the X rays with the X-ray detector;
- and
- feedback-controlling a current quantity of the electron beam on the basis of the count-number of X rays per unit time.