In the case where a specimen is imaged by a scanning electron microscope, it is intended to acquire an image of a high quality having a noise component reduced, thereby to improve the precision of an image processing. The intensity distribution of a beam is calculated on the basis of an imaging condition or specimen information, and an image restoration is performed by using a resolving power deterioration factor other than the beam intensity distribution as a target of a deterioration mode, so that a high resolving power image can be acquired under various conditions. In the scanning electron microscope for semiconductor inspections and semiconductor measurements, the restored image is used for pattern size measurement, defect detections, defect classifications and so on, so that the measurements can be improved in precision and so that the defect detections and classifications can be made high precise.