It is possible to reduce the speckle noise with simple configuration in a 2-dimensional image display device. A 2-dimensional image display device for performing image display by projecting coherent light to a projection plane includes: at least one coherent light source (1a, 1b, 1c) for outputting coherent light; a polarized state modulation unit (6) for modulating at least one of the polarized state and the phase of the coherent light from the coherent light source; and a birefringent diffusion plate (7) for spatially changing the phase of the coherent light from the polarized state modulation device. The polarized state of the light spot on each pixel of the image displayed on the projection plane is changed spatially and temporally so as to form various speckle patterns.