In a radiation detector having a radiation-stimulated light emitting scintillator and a photodetector for receiving the light emission from the scintillator, the scintillator is formed of a layer of phosphor particles and a light scattering layer is provided in an optical path between the phosphor particle layer and the photodetector. Light generated in the surface of the scintillator is scattered and absorbed by the light scattering layer in some degree so that the reduced quantity of light incident upon the photodetector lowers the output of the photodetector. This effect is balanced with the lowering of the photodetector output due to the absorption and scattering of light generated at the inner parts of the scintillator and further removes anisotropic light emission. As a result, signal-to-noise ratio is greatly improved. A shielding layer between the scintillator and photodetector prevents secondary radiation such as scattered and fluorescent radiation from reaching the photodetector. The shielding layer can also serve as the scattering layer.
