[Problem] To reduce the blurring of radiographic images that arises from radiation a direction that is slanted with respect to the radiation detector being detected across a plurality of pixels in the radiation detector.[Solution] A radiation detector for detecting irradiated radiation that includes: a converting layer (101) for converting radiation irradiated from a radiation source capable of irradiating radiation from two imaging directions, which are different from each other, into electric charges and a plurality of pixel electrodes (102a, 102b) for collecting the converted charges. In the radiation detector, when at least one of the two imaging directions forms a specified angle θ with respect to the direction that is orthogonal to the detector plane of the radiation detector, the thickness d of the converting layer (101) and the sizes p of the pixel electrodes (102a, 102b) satisfy the condition: d·tan θ < k·p (k is a constant of 1 or less).
