A radiographic imaging system comprising: a pressing plate that fixes a breast; a radiation irradiation section that irradiates radiation onto the breast fixed by the pressing plate from different imaging angles; and a radiation detector (510, 542) that includes a plurality of pixels that are arrayed in a honeycomb pattern and have a hexagonal shaped pixel region, each pixel generating and reading-out charges according to the radiation irradiated from the radiation irradiation section, the radiation detector (510, 542) outputting a first radiation image of a first resolution formed from image data of single-pixel units, or a second radiation image of a second resolution lower than the first resolution and formed from image data read-out from multi-pixel units formed by a number of adjacent pixels by carrying out binning processing according to the number of pixels of the multi-pixel units; characterized by a setting section (44, 54) that sets tomosynthesis imaging to be performed in a first mode or a second mode; a control section that, in cases in which the first mode is set by the setting section, performs tomosynthesis imaging by irradiating radiation from the radiation irradiation section at each imaging angle in a first imaging angle range and outputs a plurality of the first radiation images from the radiation detector (510, 542), and, in cases in which the second mode is set by the setting section, performs tomosynthesis imaging by irradiating radiation from the radiation irradiation section at each imaging angle in a second imaging angle range included in the first imaging angle range and narrower than the first imaging angle range and outputs a plurality of the second radiation images from the radiation detector (510, 542); and a tomographic image generation means that generates a plurality of tomographic images reconstructed with reference to a detection face of the radiation detector (510, 542) based on a plurality of the first radiation images or a plurality of the second radiation images output from the radiation detector, wherein, in cases in which the setting of the setting section is the second mode, the control section controls the radiation irradiation section such that the radiation amount irradiated onto the breast is an amount smaller than in the first mode according to the number of pixels of the multi-pixel units. a pressing plate that fixes a breast; a radiation irradiation section that irradiates radiation onto the breast fixed by the pressing plate from different imaging angles; and a radiation detector (510, 542) that includes a plurality of pixels that are arrayed in a honeycomb pattern and have a hexagonal shaped pixel region, each pixel generating and reading-out charges according to the radiation irradiated from the radiation irradiation section, the radiation detector (510, 542) outputting a first radiation image of a first resolution formed from image data of single-pixel units, or a second radiation image of a second resolution lower than the first resolution and formed from image data read-out from multi-pixel units formed by a number of adjacent pixels by carrying out binning processing according to the number of pixels of the multi-pixel units; characterized by a setting section (44, 54) that sets tomosynthesis imaging to be performed in a first mode or a second mode; a control section that, in cases in which the first mode is set by the setting section, performs tomosynthesis imaging by irradiating radiation from the radiation irradiation section at each imaging angle in a first imaging angle range and outputs a plurality of the first radiation images from the radiation detector (510, 542), and, in cases in which the second mode is set by the setting section, performs tomosynthesis imaging by irradiating radiation from the radiation irradiation section at each imaging angle in a second imaging angle range included in the first imaging angle range and narrower than the first imaging angle range and outputs a plurality of the second radiation images from the radiation detector (510, 542); and a tomographic image generation means that generates a plurality of tomographic images reconstructed with reference to a detection face of the radiation detector (510, 542) based on a plurality of the first radiation images or a plurality of the second radiation images output from the radiation detector, wherein, in cases in which the setting of the setting section is the second mode, the control section controls the radiation irradiation section such that the radiation amount irradiated onto the breast is an amount smaller than in the first mode according to the number of pixels of the multi-pixel units.