A defect inspecting apparatus comprising: an inspection region dividing section which divides a defect inspection region of a wafer on which a circuit pattern is formed into a plurality of inspection subregions; a pattern density calculating section which calculates the pattern density of each of the inspection subregions on the basis of design data of the circuit pattern; an inspection execution region and sensitivity rank setting section which assigns a sensitivity rank based on the pattern density to a plurality of inspection execution regions, each including a plurality of the inspection subregions; and a defect inspecting section which sets an inspection parameter on the basis of sensitivity ranks of the inspection execution regions and inspects the inspection execution regions for a defect.