PURPOSE: To enable the three-dimensional structure of the sample to be quantitatively grasped through observation on the spot by scanning is primary electron beam to branch it into two beams which are then obliquely irradiated upon one spot on the sample.

CONSTITUTION: An electron beam passing through an objective diaphragm 25 is scanned by a primary scanning coil 26, which is located under the objective diaphragm 25, at a scanning frequency sufficiently lower than that of a secondary scanning coil 28 to branch the electron beam into two beams. The thus branched electron beams are then focused upon one sport on a sample 29. In this stereoscanning-type electron microcsope, one detector 30 is used and it is connected to CRTs 32 and 33 thereby displaying the signal from the left amplifying system on the CRT32 and that from the right amplifying system on the CRT33. Therefore, it is possible to produce a three-dimensional image of the sample surface by simultaneously observing the image screens of the CRTs 32 and 33. Consequently, it is possible to quantitatively grasp the three-dimensional structure of the sample 29 through observation on the spot.