<p>A diamond element is mounted on an insulating base material having a thickness of not more than 3 mm provided with one pair of metal interconnects. In the diamond element, an insulating diamond layer to act as a detection layer is deposited on a substrate, and one pair of interdigitated electrodes are deposited on the surface of this insulating diamond layer. The interdegital electrodes of the diamond element are connected via wires to the metal interconnects deposited on the insulating base material. The insulating base material may transmit ultraviolet radiation to be detected. The diamond sensor is capable of stably detecting ultraviolet radiation even when the distance between a lamp and an irradiation object is short.</p>
