To provide a radiation image photographing device for reducing an effect of change of a bias voltage to be applied to respective radiation detection elements.

The radiation image photographing device 1 includes: a substrate 4 having a plurality of radiation detection elements 7, which are two-dimensionally arrayed in respective areas r divided by mutually intersected scanning lines 5 and signal lines 6, and a plurality of bias wires 9, which are connected to the respective radiation detection elements 7, apply the bias voltage to the respective radiation detection elements 7 from a bias power supply 14, and are arranged one by one in each string of the radiation detection elements 7 among a plurality of two-dimensionally arrayed radiation detection elements 7; and wire connection 10 for bonding a plurality of bias wires 9. The bias wires 9 are connected to the respective wires Fa of a flexible printed circuit board F, respectively. The ends of the respective wires Fa on the opposite side of the ends connected to the bias wires 9 are bonded on a substrate 33 different from the substrate 4 to the wire connection 10 where a resistance value per unit length is smaller than that in each bias wire 9.