PURPOSE: To select an optimum discharge passage width so as to uniform the discharge, and to make a complicated electrode unnecessary, by forming unitary a partition wall in a discharge gas housing container and a side surface plate, by bending a series of plate form substance.

CONSTITUTION: A side surface plate SF makes the outer form of a discharge gas housing container, a space combining a pair of discharge electrodes DE is made as a discharge passage, and a plane form luminous member with the form same as the discharge gas housing container is formed. A partition wall PW makes the collection of discharge passages same as the discharge gas housing container, and the discharge passage width is made the same throughout the discharge passages in respect of the evenness of discharge. And the side surface plate Sf and the partition wall PW are made in a unitary structure made by bending precessing a single plate form substance. A pair of electrode lead-in terminals TE are provided at the interval d less than two times the discharge passage width W, and furthermore, the terminals TE are used as a side surface plate or a rear side plate to facilitate the connection of a power source. And in a type to add an auxiliary electrode to the fluorescent lamp, the partition wall PW and the side surface plate SF can be utilized as an auxiliary electrode.