1. A radiation image capturing system comprising: a plurality of image capturing apparatus of different specifications for capturing a radiation image of a subject; a processor for controlling the image capturing apparatus according to predetermined image capturing conditions; an image capturing condition setting unit for setting the image capturing conditions to be appropriate for an image capturing apparatus selected among the plurality of image capturing apparatus; and an image capturing condition changer for, when the image capturing apparatus is changed, changing the image capturing conditions to be appropriate for the changed image capturing apparatus, wherein the processor controls the changed image capturing apparatus according to the changed image capturing conditions.