A projection apparatus comprising: an optical device to diffuse a coherent light beam; an irradiation unit to irradiate a coherent light beam to the optical device so that the coherent light beam scans on the optical device; a color generator to perform wavelength conversion of and transmission of light beams in a first illumination zone illuminated with the coherent light beam diffused by the optical device, in a time division manner; at least one relay optical system to change the travel direction of a light beam wavelength-converted by the color generator and the travel direction of a light beam that has transmitted the color generator to generate an illumination light beam which illuminates a second illumination zone; a spatial light modulator in the second illumination zone to generate a modulated image based on the illumination light beam to the second illumination zone; and a projection optical system to project the modulated image generated by the spatial light modulator onto a diffusing screen, wherein the first illumination zone and the second illumination zone have a conjugate relationship with each other, and the color generator comprises: a fluorescent portion to be excited by the coherent light beam diffused by the optical device to generate a light beam in a wavelength range different from a wavelength range of the light beam diffused by the optical device; and a transmission portion to transmit the coherent light beam diffused by the optical device, without diffusing the coherent light beam diffused by the optical device, wherein the color generator cyclically switches the coherent light beam diffused by the optical device to be incident either on the fluorescent portion or on the transmission portion, and transmits the light beam that the fluorescent portion has generated by wavelength conversion to be incident on the relay optical system, together with a light beam that has been transmitted through the transmission portion. an optical device to diffuse a coherent light beam; an irradiation unit to irradiate a coherent light beam to the optical device so that the coherent light beam scans on the optical device; a color generator to perform wavelength conversion of and transmission of light beams in a first illumination zone illuminated with the coherent light beam diffused by the optical device, in a time division manner; at least one relay optical system to change the travel direction of a light beam wavelength-converted by the color generator and the travel direction of a light beam that has transmitted the color generator to generate an illumination light beam which illuminates a second illumination zone; a spatial light modulator in the second illumination zone to generate a modulated image based on the illumination light beam to the second illumination zone; and a projection optical system to project the modulated image generated by the spatial light modulator onto a diffusing screen, a fluorescent portion to be excited by the coherent light beam diffused by the optical device to generate a light beam in a wavelength range different from a wavelength range of the light beam diffused by the optical device; and a transmission portion to transmit the coherent light beam diffused by the optical device, without diffusing the coherent light beam diffused by the optical device,