A defect inspection method includes generating and applies a charged beam to a sample with patterns; controlling a shape of the charged beam so that a beam width in a first direction perpendicular to an optical axis differs from a beam width in a second direction perpendicular to the optical axis and the first direction, while substantially maintaining a cross-sectional area of the beam; scanning the sample with the charged beam having the controlled shape; and detecting charged particles from the sample by irradiation of the charged beam and detects a defect of the patterns. Assuming that the beam width of the charged beam in the first direction is smaller than that in the second direction, the first direction is set to a direction in which an interval between adjacent patterns becomes a minimum value and the sample is scanned in the second direction.