An ozone generating device including an excimer lamp having an arc tube containing a luminescent gas, a first electrode, and a second electrode. The arc tube has a first end portion and a second end portion, a first diameter-reduced portion provided continuously from the first end portion, a diameter of which decreases as a distance from the first end portion increases, and a second diameter-reduced portion provided continuously from the second end portion, a diameter of which decreases as a distance from the second end portion increases, the first electrode is provided for an outer periphery surface of the first end portion, the second electrode is provided for an outer periphery surface of the second end portion, the arc tube is fixed via the cylindrical portion, and the first electrode is not provided over the first diameter-reduced portion, and/or the second electrode is not provided over the second diameter-reduced portion.