An inspection device includes: an analyzer to calculate a parameter representing a feature of image data of an object having no defect by performing dimensionality reduction on the image data, and perform dimensionality reduction on image data of an object to be inspected by using the parameter; a restorer to generate restored data obtained by restoring the image data of the object to be inspected subjected to the dimensionality reduction; a corrector to filter the restored data by using a filter for correcting an error between the restored data and the image data of the object to be inspected, thereby generating corrected restored data; a determiner to output a determination result indicating whether the object to be inspected is defective, based on a difference of each pixel between the image data of the object to be inspected and the corrected restored data; and an interface to output the determination result.