A radiation-irradiation device can perform imaging in a small radius while receiving a radiation detector. For this purpose, the radiation-irradiation device includes a leg unit, a radiation source unit, an arm unit that supports the radiation source unit, and a body unit (20) that is an arm support unit supporting the arm unit. Further, radiation-irradiation device includes a cradle (25) that supports one edge portion of a radiation detector (80) detecting radiation and having the shape of a rectangular flat plate and is mounted on the body unit (20) so as to be movable between a first position at which the radiation detector (80) is held along a flat surface (21a) of the body unit (20) and a second position at which at least an opposite edge portion of the radiation detector opposite to the one edge portion of the radiation detector (80) is held at a position away from the body unit (20).
