Ultraviolet irradiation device comprising a luminous tube, an internal electrode, an external electrode, and a cooling section

The present invention provides an ultraviolet irradiation device that can increase a degree of uniformity. An ultraviolet irradiation device according to an embodiment includes: a luminous tube extending in a first direction, having a cylindrical shape, and having an internal space filled with gas; an internal electrode provided inside the luminous tube; an external electrode provided outside the luminous tube; and a cooling section having a recess extending in the first direction. The external electrode is provided with: an electrode body arranged between the outer surface of the luminous tube and the inner surface of the recess of the cooling section, and facing the internal electrode; and a plurality of mounting parts respectively provided at two end portions of the electrode body in a second direction perpendicular to the first direction. The plurality of mounting parts are mounted to a surface at the recess of the cooling section in the first direction. The distances between centers of the plurality of m