A radiation image capturing device includes: an image capturing unit that captures a radiation image using irradiated radiation; a radiation detection unit that detects the radiation; a determination unit that determines whether image capturing preparation is completed; and a control unit that starts detection of the radiation by the radiation detection unit, in a case in which the determination unit determines that the image capturing preparation is completed, and controls the image capturing unit to capture a radiation image, in a case in which the radiation detection unit detects the radiation.