To provide an ultraviolet ray detecting element, having constant sensitivity regardless of the positional relationship between an ultraviolet ray radiating source and an ultraviolet ray detecting element, when both the sides have the same distance, and the sensitivity characteristic of a wide visibility angle.

In an ultraviolet ray detecting element having a cathode 6 for emitting an electron when receiving an ultraviolet ray, an anode 5 for receiving the electron, and a glass bulb 4 for internally providing both the electrodes 6 and 5, the cathode 6 has a cathode body 6a formed spherically, the anode 5 has one or plural bar-like bodies 5g, and the bar-like body 5g is arranged receding by a given distance from the surface of the cathode body 6a, and is provided neary uniformly over the whole surface to surround the cathode body 6a.