The present invention mitigates a sensation of enclosure and a sensation of fear in a subject inserted into an inspection space, and increases the comfort of the subject in the inspection space. A design that imparts a visual effect on the subject is formed at the inspection space inner wall (140) of an inspection device having a tubular inspection space into which the subject is inserted. The design includes a plurality of elements (150) or objects, and of the spacing between the elements or the spacing between the objects, the spacing (W) in the circumferential direction and/or spacing (P) in the lengthwise direction of the inspection space changes from the side of subject insertion towards the far end. The elements, for example, are a geometric pattern such as dots and lines, and the objects are a design that mimics nature.
