An inspection device in accordance with the present invention is configured so that a light source used for irradiating light, and a reflection-type prism that irradiates the light from the light source to a hologram provided on an inspection target that is placed downward and that diffracts light rays in different directions that are reflected from the hologram upward in the same or substantially the same direction are housed in a case. With such an arrangement, it becomes possible to provide an inspection device that can positively conduct an inspection process for identifying the genuineness of an inspection target having a hologram quickly, and is also advantageous in costs.