Provided is a flat fluorescent lamp that can emit white light composed of color components with enhanced color purity and/or white light having enhanced brightness and enhanced brightness uniformity. The flat fluorescent lamp includes a front substrate and a rear substrate separated from each other and defining a discharge space therebetween, a discharge gas filled in the discharge space and generating a first ultraviolet (UV) light with a wavelength of 260 nm or less by discharge of the discharge gas, at least a pair of electrodes inducing the discharge of the discharge gas, a second phosphor layer disposed on an inner surface of the rear substrate and including a phosphor excited by the first UV light and generating a second UV light having a wavelength of 200 to 400 nm which is longer than the wavelength of the first UV light, and a first phosphor layer disposed on an inner surface of the front substrate and including a phosphor excited by the first UV light and the second UV light and generating a visible light. Provided are also novel UV light-emitting phosphors excited by vacuum UV light and generating UV light.