PROBLEM TO BE SOLVED: To suppress misdetection about whether or not a radiation imaging device is irradiated with radiation.SOLUTION: A radiation imaging device 100 is configured by: a pixel array 101 having a plurality of pixels PIX each including a conversion element S converting and storing radiation and a connection switch element T； a bias line Vs for giving a bias potential to the pixels； drive lines G connected to control terminals of the switch elements of the pixels； a drive part 102 repeating an initialization operation for switching the switch elements between a non-conduction state and a conduction state, for each drive line group including one or more drive lines； an acquisition part acquiring a value of a current flowing in the bias line a plurality of times for each cycle from when a drive signal to a certain drive line group is switched to an ON voltage to when a drive signal to the next drive line group is switched to an ON voltage； a calculation part 130 calculating radiation information on the basis of the current value； and a determination part 131 determining presence or absence of the irradiation of radiation to the pixel array on the basis of radiation information.【課題】放射線撮像装置に放射線が照射されているか否かの誤検知を抑制する。【解決手段】放射線を変換・蓄積する変換素子Ｓと接続スイッチ素子Ｔを含む複数の画素ＰＩＸを持つ画素アレイ１０１と、画素にバイアス電位を与えるためのバイアス線Ｖｓと、画素のスイッチ素子の制御端子に接続された駆動線Ｇと、１つ以上の駆動線を含む駆動線グループごとに、スイッチ素子を非導通状態と導通状態とを切り替える初期化動作を繰返す駆動部１０２と、ある駆動線グループへの駆動信号をオン電圧へ切替え後、次の駆動線グループへの駆動信号をオン電圧へ切替えるまでの周期ごとに、バイアス線を流れる電流値を複数回取得する取得部と、電流値に基づいて放射線情報を算出する算出部１３０と、放射線情報に基づいて画素アレイへの放射線の照射の有無を判定する判定部１３１とで放射線撮像装置１００を構成する。【選択図】図１
