PROBLEM TO BE SOLVED: To heat a sample in an electron microscope to a higher temperature than conventional. SOLUTION: An electron microscope is structured so that a sample 21 to be observed can be heated without changing the lens conditions at observing, wherein a heating electron beam 5 at an accelerating voltage loser than an observing electron beam 6 is applied on an objective lens 3 as an electron lens surrounding the sample 2 placed on the optical path of the observing electron beam 6, and a heating electron beam source 1 heats the sample 2 through the lens action part of the electron lens 3. The heating of sample 2 is performed by converging the heating electron beam 5 using the acting magnetic field of the objective lens 3 for the observing electron beam 6.
