A radiation detector includes a sensor panel that includes a main surface and a plurality of photoelectric converting elements formed on the main surface, a scintillator layer that includes a plurality of columnar crystals in a scintillator material and is formed on the main surface, an intermediate layer that covers a front surface and a side surface of the scintillator layer, a resin frame that is formed on the main surface to surround the scintillator layer, and a protective plate that is bonded to the resin frame to seal the scintillator layer. The scintillator layer extends along the main surface to come into contact with the resin frame with the intermediate layer interposed therebetween.