PURPOSE: An unpatterned wafer inspector is provided to perform more reliable defect inspection, by applying different reference values to the measurement value of each region on a wafer. CONSTITUTION: A detection part(20) detects a light reflected from a wafer(100). The light is irradiated from a light source(10). The detection part includes a judgment part(30). The judgment part converts the detected light into a quantified measurement value. The judgment part judges the defect of the wafer. The wafer includes a first region and a second region. The detection part detects the light reflected from the first and the second region of the wafer. The judgment part compares a second measurement value with a first reference value. The judgment part judges the defect of the second region of the wafer.
