The present invention provides a discharge lamp which provides stable diffusion of a radiator and a stable electrode strength. The discharge lamp is provided with a cathode (20) which is provided with a sintered layer (sintered member) (24) on the front end (23) of the electrode, wherein the sintered layer is composed of a plurality of density inclination layers (26). Each density inclination layer is formed through periodically compressing the mixed powder of radiator powders such as barium oxide and high-melting-point powders such as tungsten into a dent part (25) of the cathode (20), and integrally performing SPS sintering. In each layer, the sintered member is inclined, and the density gradually reduces from the front side to the back side of the electrode.