To provide an ultraviolet light source, light and compact, with a simple structure, of low cost and with a large and uniform intensity of ultraviolet rays and a self-luminous display device equipped with the ultraviolet light source.

The ultraviolet light source 10 is of a plane type in which ultraviolet rays are generated by impressing voltage between one or a number of pairs electrodes 2 fitted on an inner wall of an enclosed vessel and one or a number of pairs of electrodes 2 equipped with mercury gas and/or rare gas sealed inside the enclosed vessel to have the mercury gas and/or the rare gas make a plasma discharge and the ultraviolet rays are taken out of the enclosed vessel. It is also provided with an auxiliary electrode 5 connected with a filament emitting thermal electrons for starting the plasma discharge for heating the filament and make it emit thermal electrons.