A radiation-irradiation device includes a leg unit, a radiation source unit, an arm unit that supports the radiation source unit, and a body unit that is an arm support unit supporting the arm unit. Further, radiation-irradiation device includes a cradle that supports one edge portion of a radiation detector detecting radiation and having the shape of a rectangular flat plate and is mounted on the body unit so as to be movable between a first position at which the radiation detector (80) is held along a flat surface of the body unit 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 is held at a position away from the body unit.
