Transparent screen and projection display unit

A transparent screen and a projection display unit capable of reducing the speckle with maintaining the brightness of the image light. A wavefront-dividing phase-modulating component 21, which divides the wavefront of the image light emitted from a Fresnel lens screen 7 and modulates the phases of the wavefronts divided, is disposed before an optical diffusing component 10 . Alternatively, a spatial frequency modulating component 22 , which modulates the spatial frequency of the image light diffused by the optical diffusing component 10 , is disposed on the light-output side (observer side) of the optical diffusing component 10.