a flat light source having a front plate and a rear part . the front plate is held at a distance from the rear part by spacers . a gaseous filling which is under a pressure lower than the ambient atmospheric pressure is introduced into the intermediate space between the front plate and rear part , and the front plate is of a glass material . to be able to produce flat light sources of this type which have a low intrinsic weight , according to this invention the front plate and / or the rear part can be configured as an at least partly thermally or chemically tempered glass pane or the front plate and / or the rear part can be configured as a glass pane which at least in areas is coated with ductile polymer material .