An electrodeless discharge lamp includes a discharge gas sealed in a lamp tube. The discharge gas includes a halide of rare earth metal. An auxiliary electrode is disposed on or adjacent to an outer periphery wall of the lamp tube such that the auxiliary electrode is capacitively coupled to an interior space of the lamp tube. A main induction coil is wound around the lamp tube and receives power from a first high frequency power source. The auxiliary electrode receives power from a second high frequency power source. In operation, the electrodeless discharge lamp attains smooth lighting upon starting or restarting.
