To provide a radioactive image photographing apparatus which performs dark read processing in a practical time while maintaining accuracy of an offset correction.

The radioactive image photographing apparatus 1,100 includes: a plurality of radioactive detecting elements 7; switch means 8; a current detecting means 43 detecting a current flowing in a device by the irradiation of radioactive rays; and a control means 22 detecting the start of the irradiation of at least radioactive rays on the basis of the value of the detected current. The control means 22 applies an off voltage Voff to each switch means 8 before radioactive image photographing and stores dark charges in each radioactive detecting element 7, applies an on voltage Von to each switch means 8 and applies the off voltage Voff to each switch means 8 again when detecting the start of the irradiation of the radioactive rays. The control means 22 applies the on voltage Von to each switch means 8 at the same time interval as the applying time T2-T1 of the on voltage Von to each switch means 8 at radioactive image photographing for dark reading processing, and conducts the dark reading processing. T1 represents the time bringing each switch means 8 to an on state and T2 the irradiation start time of radioactive rays.