A scanning electron microscope of the present invention performs scanning by changing a scanning line density in accordance with a sample when an image of a scanned region is formed by scanning a two-dimensional region on the sample with an electron beam or is provided with a GUI having sample information input means which inputs information relating to the sample and display means which displays a recommended scanning conditioHn according to the input and performs scanning with a scanning line density according to the sample by selecting the recommended scanning condition. As a result, in observation using a scanning electron microscope, a suitable scanning device which can improve contrast of a profile of a two-dimensional pattern and suppress shading by suppressing the influence of charging caused by primary charged particle radiation and by improving a detection rate of secondary electrons and a scanning method are provided.