Provided is a radiation irradiation device that can improve the degree of freedom of an arm part and can reduce the number of noise suppression components, such as a ferrite core. A radiation irradiation device includes a radiation generating part having a radiation source that generates radiation； an arm part having the radiation generating part attached to one end thereof； and a main body part having the other end of the arm part connected thereto. The main body part has a power source part including a three-phase inverter circuit. The power source part supplies a three-phase alternating current voltage to the radiation generating part via the arm part.
