To reduce exposure by continuously irradiate a large amount of radiation in a cancer tissue and intermittently irradiating pulsed radiation to normal tissues, to efficiently perform radiotherapy by recovering the normal tissues from radiation damage in irradiation intermittent periods between respective pulses, and to solve problems in radiotherapy wherein ideally radiation is irradiated on the cancer tissue alone, however, inevitably the radiation is applied to the normal tissues surrounding the circumference of the cancer tissue to cause radiation exposure and radiation damage of the normal tissues, and, for preventing it, an irradiation target region is required to be positioned in the rotation center.

Radiation emission devices 1 and 2 continuously rotates about the irradiation target region so as to continuously apply the radiation to the rotation center region and intermittently apply the pulsed radiation outside the region. While the target region is monitored by X-ray transverse tomographic image devices 3 and 4, a bed is moved 6 and 9 so that the target region precisely comes to the rotation center.