Provided is a method of inspecting a pattern defect. The method includes: applying a voltage to an object to be inspected and measuring an inspection signal generated in a pattern of the object to be inspected due to the voltage applied to the object to be inspected over time; generating an intensity image showing a relationship between an intensity of the inspection signal measured in the pattern and a time by processing the inspection signal; and detecting a pattern defect position by comparing the intensity image with a comparative intensity image.