A projection image display device includes: laser diodes which emit excitation light; a top-hat diffusing element which diffuses and provides the excitation light with a top-hat intensity distribution; a phosphor which emits light when illuminated by the excitation light diffused by the top-hat diffusing element; an integrator rod which homogenizes the light emitted by the phosphor; DMDs which modulate the light homogenized by the integrator rod; and a projector which projects the light modulated by the DMDs.