Discharge lamp and manufacturing method of electrode for discharge lamp to dissipate the heat effectively and suppress the electrode temperature

In a discharge lamp, the heat is effectively dissipated and the electrode temperature is suppressed. A closed inner space 40 is formed inside the electrode 30 of the discharge lamp 10, and the heat dissipation portions 50A, 50B facing each other along the electrode axis X are formed. (Claim 1) The feature of the discharge lamp comprises: a discharge tube; and a pair of electrodes allocated oppositely in the discharge tube; at least one electrode has an inner space; on the surface of the inner space, heat dissipation/heat absorption structures are disposed oppositely.