Scanning electron microscope and sample observation method

The present invention provides a contact hole observation technology for avoiding a situation in which it is difficult to observe a contact hole as a nonuniform charge is formed in the contact hole due to a tilted electron beam during a process for forming a preliminary charge on a sample. The present invention also provides a scanning electron microscope based on such a contact hole observation technology. During a preliminary charge process, an electron beam is allowed to become incident in a plurality of directions to perform a precharge, thereby reducing a region within the contact hole that is not irradiated with the electron beam. This reduces the number of secondary electrons that become lost on the wall surface of the contact hole, thereby making it possible to acquire information about the bottom of the contact hole. Further, the precharge is processed by dividing a precharge irradiation region into a plurality of ring-shaped regions concentric with an observation region and precharging each of the ring-shaped regions in a plurality of scanning directions.