To provide a magnetic domain observing device capable of obtaining an observation image having a good magnetic domain contrast.

In a scanning electron microscope formed so as to detect reflected electrons from a sample 2 by a reflected electron detector 10A, the magnetic domain observing device is to observe a magnetized component parallel to the perpendicular direction of an inclined axis 4 as the magnetic domain contrast as to the magnetic material sample 2 inclined with respect to an optical axis 3, and is structured so that the reflected electron detector 10A is symmetrically divided in the optical axis direction, and an computing unit to arithmetically process the detected signal of each divided reflected electron detector 10AR, 10AL is provided to observe the output of the computing unit as a magnetic domain contrast signal.