To reduce the number of component equipment and to improve economy and working efficiency by providing a deflection electromagnet, a plurality of medical treatment rooms, a rotary gantry, and the like and arranging a beam being emitted from the rotary gantry on a circumferential surface with an electromagnet for branching beams as a center.

Charged particles being accelerated to a specific energy by a charged particle accelerator 41 is branched into a medical treatment room 43 by an electromagnet 42. In this case, the direction of a magnetic field is changed or the magnetic field is set to zero. The branched beam is rotated in a vertical surface with an irradiation position 44 as a center. The beam shape is adjusted using a four-pole electromagnet 48 until the beam reaches an irradiation position 44 after passing through a rotary gantry 46 and is guided to the irradiation position 44. Also, the direction of the beam is changed by a plurality of deflection electromagnets 42 and the beam is carried to the irradiation position 44, thus reducing the beam path length after the electromagnet 42 for branching beams, reducing the installation space of an irradiation device, and reducing the deflection angle of the electromagnet for deflection beams, reducing the scale of the device, and facilitating adjustment.