An inspection device includes an image reader that generates a scan image, an inspector that inspects an inspection target image formed on a storage medium, by comparing a scan image with a reference image, a storage that stores the reference image, and a hardware processor that stores into the storage the reference image generated as the scan image by reading with the image reader an image formed on a recording medium by the image former on a basis of a second print job for generating the reference image, determines whether the reference image stored in the storage satisfies a predetermined condition when a data amount of the reference image stored in the storage becomes equal to or larger than a predetermined amount, and deletes the reference image determined to satisfy the predetermined condition from the storage.