The present invention has an object to provide a scanning electron microscope which suppresses a potential gradient produced by preliminary charge without changing lens conditions of an electron microscope. As an aspect to achieve the above object, there is proposed a scanning electron microscope in which a scanning deflector is controlled so that a second beam is scanned to detect electrons released from a sample after scanning a first beam on the sample to charge the surface of the sample and the first beam is scanned so that charge density in a surrounding part within a scanned area by the first beam is increased relatively as compared with a center part within the scanned area by the first beam.