A radiographic imaging device including: a sensor portion that generates an output signal according to an irradiated amount of irradiated radiation； a detection means that based on the output signal detects a radiation irradiation start of radiation irradiated from a radiation source during capture of a radiographic image； a noise data generation means that, based on an output signal from the sensor portion in a non-irradiation state of radiation from the radiation source, generates noise data relating to noise incorporated in the output signal； a control means that controls detection sensitivity to radiation irradiation start in the detection means according to a degree of variation in noise level expressed by the noise data； and an imaging means that captures the radiographic image after radiation irradiation start has been detected by the detection means.
