An irradiation apparatus radiates a particle beam after forming the beam for plural layers. A dose monitor measures a dose in real time. A dose evaluation unit evaluates an irradiation dose for each layer on the basis of a value measured by the dose monitor and a dose calibration factor set for each layer. An irradiation control section performs radiation control for each layer on the basis of an evaluation result of the dose evaluation unit. An interpolation value generation unit uses actual-measurement dose-calibration factors obtained by radiating a particle beam to a simulated phantom provided with a calibration dosimeter, to generate an interpolation estimation value of the dose calibration factor. For each layer subject to the interpolation value, and based on an irradiation condition of that layer, the interpolation value generation unit performs weighting on each of the actual-measurement dose-calibration factors.
