A method of adjusting a sensitivity parameter value for substrate defect inspection used in a substrate defect inspection apparatus compares, for each pixel value of a selected virtual inspection substrate, using reference pixel data to be used after adjustment, the deviation amount from an allowable range corresponding to the position thereof and the sensitivity parameter value before the adjustment when each pixel value is deviated from the allowable range, and updates the deviation amount as a new sensitivity parameter value when the deviation amount exceeds the sensitivity parameter value and a difference between the deviation amount and the sensitivity parameter value is equal to or less than a threshold value.