A method for manufacturing a high pressure mercury lamp having a high pressure resistance strength includes an electric field application step of applying an electric field to at least a light emitting part while keeping the high pressure mercury lamp at a high temperature. As a result of the electric field application step, impurities such as hydrogen and an alkali metal existing in a discharge space and in glass used for forming the light emitting part (1) and sealing parts (2) can be reduced, with it being possible to suppress blackening and devitrification during lighting.