the tem image are observable at the same time if the change over switch 46 is set at stem mode on the other hand the fluorescent plate 23 is opened and the stem image is displayed on the cathode ray tube 25 in response to a signal from the scanning transmitted electron detector 45 in this way not only the sem and stem images are observable from the viewing window 24 but also such a scanned image as the sem image on the cathode ray tube 25 can be observed from the viewing window 24 for comparison with the tem image further the data required for the tem image is easily observed without looking aside thus improving the workability greatly referring again to fig2 in addition to the above mentioned data a reflected electron image an x ray image a television electron microscope image or the like may be displayed on the cathode ray tube 25 it will also be easily understood that required data can be displayed on the cathode ray tube 25 even in sem or stem mode for displaying data on the cathode ray tube 25 the well known character generater is conveniently used also if the latest microcomputer and television numerical display ram are used characters and numerals are displayed very easily so that the name of the.