A projection display apparatus (1) includes a wavelength conversion element (11) that converts a wavelength of light from a light source, a driver (13) that rotates the wavelength conversion element, and an internal power supply (15) that stores power in advance and to be used for an operation of the projection display apparatus after a supply of power from an external power supply is cut off, and the driver rotates the wavelength conversion element at the predetermined number of rotations per unit time by using the power of the internal power supply.