PURPOSE: To provide a discharge lamp lighting device having a constant luminous flux and capable of controlling color temperature.

CONSTITUTION: A power source frequency conversion device 11 varies the frequency of a power source connected to respective lighting circuits to change the impedance of capacitive and inductive ballasts 9 and 10, and a high power source frequency relatively enlarges the luminous flux of an arc tube 1 on a mercury lamp side to which the capacitive ballast 9 is to be connected to change the luminous color of a discharge lamp 4 to a high color temperature side to obtain light having a refreshing sense. Conversely, a low power source frequency relatively enlarges the luminous flux of an arc tube 2 on a high pressure sodium lamp side to which the inductive ballast 10 is connected to obtain light of a warm color system having low color temperature.