Size and cost of an apparatus are reduced by reducing the optical path length of light emitted from a light source while enhancing utilization efficiency of the light source. A projection image display (50) employs LEDs (51R, 51G, 51B) as the light source and directs an emitted light beam to enter an optical integrator (60). The optical integrator (60) is formed by bonding four block members (61-64) in the longitudinal direction wherein a dichroic mirror (65R) reflecting an R light beam and transmitting G and B light beams, a dichroic mirror (65G) reflecting a G light beam and transmitting R and B light beams, and a dichroic mirror (65B) reflecting a B light beam and transmitting R and G light beams are provided integrally on the inclining bonding face of each block member (61-64). Each dichroic mirror (65R, 65G, 65B) reflects the light emitted from each LED (51R, 51G, 51B) and propagates them through the optical integrator (60) while reflecting totally and outputs a uniform light beam from an exit face (60b).