A radiation detector and a radiological image radiographing apparatus capable of improving the quality of an obtained radiological image without causing an additional cost are provided. A first scintillator configured to include columnar crystals generating first light corresponding to a radiation emitted through a TFT substrate is laminated on the other surface of the TFT substrate that has a first photoelectric conversion element, which has one surface from which a radiation is emitted and the other surface from which at least one of the first light and the second light is emitted and which generates electric charges corresponding to the light, and a first switching element. A second scintillator which generates second light corresponding to a radiation emitted through the first scintillator and has different energy characteristics of absorbed radiations from the first scintillator is laminated on a surface of the first scintillator not facing the TFT substrate.