PROBLEM TO BE SOLVED: To provide a radiation irradiation device that can properly manage the residual capacity of a battery without being affected by the internal resistance of the battery.SOLUTION: A radiation irradiation device has a radiation generating unit that generates radiation, a battery unit 60 that supplies the radiation generating unit with power, and a residual capacity calculation unit 22a that calculates a residual capacity of the battery unit 60. The residual capacity calculation unit 22a calculates the residual capacity of the battery unit 60 on the basis of a current flowing in the battery unit 60, an internal resistance of the battery unit 60 and a voltage of the battery unit 60.SELECTED DRAWING: Figure 4【課題】本発明は、上記の問題に鑑み、バッテリの内部抵抗の影響を受けることなく、バッテリの残容量を適切に管理することができる放射線照射装置を提供する。【解決手段】放射線を発生する放射線発生部と、放射線発生部に電力を供給するバッテリ部６０と、バッテリ部６０の残容量を算出する残容量算出部２２ａとを備え、残容量算出部２２ａが、バッテリ部６０に流れる電流とバッテリ部６０の内部抵抗とバッテリ部６０の電圧とに基づいて、バッテリ部６０の残容量を算出する。【選択図】図４
