An inspection apparatus has a configuration which can suppress attenuation of an electromagnetic wave caused by an environment surrounding the inspection apparatus and can readily prevent an unwanted substance from being contaminated into a propagation path of the electromagnetic wave. The inspection apparatus includes a substrate having therein a structure for holding an inspected object, an electromagnetic wave transmitting portion having an antenna structure and an electromagnetic wave receiving portion having an antenna structure. The electromagnetic wave transmitting portion and the electromagnetic wave receiving portion are disposed in contact with the substrate.