A fluorescent lamp 1 is constructed in which more than two lead wires (5), (6), (11) and (12) are connected to respective electrodes (3) and (4) of both end portions of a glass tube (2), the glass tube (2) having a uniform diameter of less than 6.5 mm. Also, when the fluorescent lamp 1 is manufactured, an electrode assembly in which two glass beads are fixed to more than two lead wires extended from the electrodes, mercury amalgam being welded to the lead wires is used, the electrode assembly is temporarily fastened by welding the inside glass bead to the glass tube, mercury is evaporated by heating the mercury amalgam and the inside of the glass tube is sealed by welding the outside glass bead to the glass tube.