Inspection device and method of inspecting inspection target using the same

An inspection device for inspecting an inspection target, the inspection device comprising:

• an imaging circuit which captures the inspection target and outputs image data corresponding to the inspection target;
• a data extraction circuit which receives the image data and extracts inspection data corresponding to an inspection area of the inspection target from the image data;
• a setting circuit which sets a threshold value based on a grayscale value of comparative data compared with the inspection data in a manner in which the threshold value increases as the grayscale value of the comparative data increases and the threshold value decreases as the grayscale value of the comparative data decreases;
• and
• an inspection circuit which determines that the inspection target is defective in a state in which a difference between the inspection data and the comparative data exceeds the threshold value,
• wherein the grayscale value range of the comparative data is classified into a plurality of sections,
• wherein the threshold value has a linear relationship with the grayscale value of the comparative data in each of the plurality of sections, and
• wherein a slope in a section corresponding to higher grayscale value is greater than a slope in a section corresponding to lower grayscale value.