An objective of the present invention is to provide a particle beam treatment device which performs the scanning irradiation in which appropriate dose calibration can be performed. A particle beam treatment device comprising an irradiation nozzle which moves a pencil beam in the lateral direction which is perpendicular to the advancing direction a dose monitor which measures the dose of a particle beam which is emitted from the irradiation nozzle a treatment planning part which sets the irradiation dose set value which is applied to a target volume and a treatment controlling part which controls the irradiation dose which is applied to a target volume based on irradiation dose set value which is set by a measurement value of the dose monitor and the treatment planning part, wherein the treatment planning part stores PDD which is the absorbed dose distribution data in the depth direction which is prepared in advance using the absorbed dose at the reference depth which is a predetermined position which is nearer to an incident side of the pencil beam than the position of Bragg peak as the reference and calculates the irradiation dose set value using the absorbed dose at the reference depth as the reference.
