A method and apparatus for inspecting a wafer in which a focused charged particle beam is irradiated onto a surface of a wafer on which patterns are formed through a semiconductor device fabrication process, a secondary charged particle image of a desired area of the wafer is obtained by detecting secondary charged particles emitted from the surface of the wafer, and information about image feature amount of each pattern within the desired area from the obtained secondary charged particle beam image. The information about image feature amount is compared with a preset value, and on the basis of a result of the comparison, a quality of patterns which have been formed around the desired area is estimated, and information of a result of the estimation is outputted.