HIGH PRESSURE DISCHARGE LAMP AND ITS STARTING METHOD

PROBLEM TO BE SOLVED : To provide a high pressure discharge lamp and its starting method, in which the starting voltage thereof can be reduced. SOLUTION : The high pressure discharge lamp comprises a discharge tube 1 having a discharge space 2 filled with at least a kind of rare gas, a pair of electrodes 3 projected into the discharge space 2 to facing each other, a current supply conductor 5 that supplies current to the electrode 3, a sealing part 4 extending from the discharge tube 1 to airtightly seals the current supply conductor 5, an outer tube 8 surrounding the periphery of the discharge tube 1 and airtightly adhered to the discharge tube 1, wherein a gas that make possible dielectric barrier discharge with a lower discharge voltage than that of in the discharge tube 1 is filled in a space surrounded by the outer tube 8.