A projection image display device including a display plane for displaying an image, a projection mechanism projecting an image on the display plane, and an imaging mechanism arranged on the same side of the display plane as the projection mechanism for imaging the display plane. The imaging mechanism is arranged at a position where a position symmetric with respect to the display plane of the projection mechanism is out of the range of the field angle of the imaging mechanism. By arranging the imaging mechanism at a position where no direct reflecting light of the light source of the projection mechanism comes, it is possible to prevent generation of a hot spot.