| 摘要 |
PROBLEM TO BE SOLVED: To easily correct shift of optical axis of electron beam, astigmatism of a permeation image, and the like generated by heating ferromagnetic material by providing a magnetic field control mechanism for varying magnetic field near a sample according to a sample temperature. SOLUTION: A sample 2 is heated by a heater 3. A temperature of the sample 2 is detected by a temperature detector 7 and inputted into a comparing circuit 13 in a magnetic field control part 10 at any time. The inputted temperature is compared with the Curie temperature of the sample 2 previously inputted into a storage circuit 11 in the comparing circuit 13. When the inputted temperature and the Curie temperature are different, the magnetic field control part 10 controls a magnetic coil power source 9 to be constant and the current flowing through a magnetic coil 8 is constant. When the inputted temperature and the Curie temperature become the same temperature, the magnetic field control part 10 controls the magnetic coil power source 9 from a magnetic coil power source control part 12, so as to cut-off the current flowing through the magnetic coil 8 for the ferromagnetic body to become a paramagnetic material.
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