Abstract: A semiconductor chip with bumps to be inspected is placed directly below a CCD, which captures an image of the bumps under dark field illumination. A reference window is set around each bump in the image. The reference window is enlarged or reduced or divided into subwindows such that optimal windows are provided for extraction of characteristic values of various defects. Characteristic values of particular defects are extracted from the image data within the corresponding optimal windows. The characteristic values for the bumps are statistically processed to obtain an evaluation value having a permissible range. The characteristic value of each bump is compared with the evaluation value and when the comparison indicates that the characteristic value is outside of the range, the bump is decided as a defective bump.