To provide a fluorescent lamp comprising a light-emitting tube composed of quartz glass with discharge gas containing sealed xenon ； a pair of electrodes that are formed in the length direction of the light-emitting tube and faced each other via a dielectric interposed there between； and an inner phosphor layer formed on the inside surface of the light-emitting tube. An aperture part of the fluorescent lamp is formed on the periphery part of the light-emitting tube where the inner phosphor layer is not formed. The fluorescent lamp provides a structure for preventing the phosphor layer from deterioration and emitting light stably. The present invention is characterized in arranging an external tube to cover the light-emitting tube and forming an external phosphor layer on an external surface of the light-emitting tube that correspond to the aperture part.
