A radiation imaging apparatus (10) configured to capture a radiographic image includes a electromagnetic ray generating unit (14) configured to irradiate a subject (M) with a plurality of electromagnetic rays generated by a plurality of electron sources disposed in a one-dimensional or two-dimensional array and an electromagnetic ray detection unit (12) configured to capture a plurality of first radiographic images based ON detection of the plurality of electromagnetic rays which have different irradiation angles and passed through the subject (M), an area specification unit (26) configured to specify an object area using the plurality of first radiographic images captured by the electromagnetic ray detection unit and a determination unit (25) configured to determine an electron source to be driven from the plurality of electron sources based ON the object area specified by the area specification unit. A second radiographic image is captured based ON the electromagnetic rays generated by the electron source determined by the determination unit (25).
