Discharge lamp having electrode part with negative electron affinity

The invention relates to a discharge lamp equipped with a gastight discharge vessel containing a gas and equipped with electrodes, at least one of the electrodes comprising In a capacitively coupled discharge lamp the electrode comprises a dielectric material that during operation is in contact with the discharge. The impedance of the dielectric material is small and its electron affinity is negative. In this way it is realized that the discharge lamp can be operated efficiently at low frequencies (less than 500 KHz).