A radiation image detector is provided. The radiation image detector is constituted by: a photoconductive layer that generates charges when electromagnetic waves are irradiated thereon; a common electrode to which a predetermined voltage is applied, provided on one side of the photoconductive layer; a plurality of divided electrodes that output signals corresponding to charges which are generated within the photoconductive layer, provided on the other side of the photoconductive layer; and protective layers that cover the edges of the divided electrodes, the edges being the side surfaces and portions of surfaces of the divided electrodes, which are continuous with the side surfaces, that face the photoconductive layer. The interfaces between the protective layers and the photoconductive layer are smooth surfaces across the entireties thereof.