A radiation detection apparatus including a scintillator layer configured to convert radiation into light； a light sensor layer including a plurality of light sensors configured to detect light emitted from the scintillator layer； and a reflection layer configured to reflect light emitted from the scintillator layer. The scintillator layer is arranged between the light sensor layer and the reflection layer. The following condition is satisfied: 0.375 ‰¤ 100 - x / 100 - y % <； 3.75 where the average conversion efficiency in a region of 25% of the thickness of the scintillator layer from a reflection layer side is set to 100 as a reference, x is the average conversion efficiency in a region of 25% of the thickness of the scintillator layer from a light sensor layer side, and y(%) is the reflectance of the reflection layer.
