A method of manufacturing a surface emitting fluorescent lamp, designed to reduce a total thickness of the surface emitting fluorescent lamp, and to allow easy sealing of a gas injection port. The method comprises forming at least one injection port connected to one side of a discharge channel in a horizontal direction of the fluorescent lamp to communicate with the discharge channel simultaneous with forming a discharge space, providing a sealant within the gas injection port in order to seal the gas injection port, providing a mercury pellet containing mercury to one side of the sealant, vacuum exhausting the discharge space of the fluorescent lamp, diffusing inert gas into the discharge space, and diffusing mercury vapor evaporated from the mercury pellet into the discharge space. Then, the sealant is melted, and seals a connection between the gas injection port and the discharge channel.