To provide a lighting device that solves discharge instability due to phase interference among fluorescent lamps, and makes a start of the fluorescent lamp stable, and enhances simplification of composition and efficiency without unevenness in brightness and chromaticity of an illuminated surface in a lighting device.

This lighting device is characterized in that a tubular bulb (2) is formed, in which mercury and at least one inert gas of argon, krypton, xenon and neon are sealed, both ends of which are blocked, and in the inner face of which a phosphor film is applied, and external electrodes (4) are arranged on the outsides of both ends of the tubular bulb (2), and a plurality of fluorescent lamps (1) is adjacently arranged there, and the external electrodes (4) on each one end and the other end of the plurality of fluorescent lamps (1) are commonly connected together and are connected to one boosting lighting circuit (6).