A method of lighting a high-pressure discharge lamp is configured to change a power to be supplied to the high-pressure discharge lamp in accordance with a luminance parameter of an image content. The method includes switching between a low temperature operation and a high temperature operation so as to maintain a condition that mercury encapsulated into an arc tube part of the high-pressure discharge lamp constantly partially deposits without evaporating. The low temperature operation is performed where the temperature in the arc tube part is less than or equal to the deposition temperature of the mercury, whereas the high temperature operation is performed where the temperature in the arc tube part is greater than the deposition temperature of the mercury.