A projection apparatus that provides flicker reduction according to the cause of flicker, to thereby properly reduce flicker without unnecessarily bringing about characteristic degradation is disclosed. Light for projecting a projection image onto a projection surface is output from a light source, and separated into light beams of a plurality of colors. Images corresponding to the light beams of the plurality of colors are formed on display units. The light beams of the plurality of colors having passed through the display units are synthesized and projected onto the projection surface. Fluctuations in the light quantity of the light beams of the plurality of colors having passed through the display units and yet to be input to the color synthesis unit are detected. Detection results are analyzed, and it is determined whether flicker caused by the display units or flicker caused by the light source is occurring in the projection image.