Sample drift in a scanning electron microscope is suppressed which is caused by a change in room temperature or associated with operation of motors for driving a sample stage. Supply currents to the motors during movement of the sample and a stop of the sample movement are controlled so that the supply currents have the same level or so that a maximum difference in level between the supply currents is 20%. This lessens any changes in the amounts of heat generated by the motors, thereby reducing sample drift during observation.
