Providing a radiation intensity measurement apparatus for the treatment of cancer brachytherapy which can be measured simply and accurately the radiation intensity of the source cartridge is still packaged in sterile condition. An apparatus for measuring the radiation intensity of the source S of the state of being filled in the cartridge C, and the radiation intensity measuring means for measuring the radiation emitted from the source S, a holding means 30 for holding the cartridge C, held consists of a moving means for radiation intensity measuring means to move the means 30, moving means, so as to move along in the direction holding means 30 is perpendicular to the axial direction of the slit 15h, guide for guiding the movement of the holding means 30 so as to pass through a position in which all sources of a state where the parts were filled in the cartridge C is provided with a slit 15h in the interior space of the housing portion, and a moving unit for moving the holding means 30 I is characterized by.カートリッジが滅菌状態に包装されたままで線源の放射線強度を簡単かつ精度よく測定することができるがん治療用密封小線源の放射線強度測定装置を提供する。カートリッジCに充填された状態の線源Sの放射線強度を測定する装置であって、線源Sから放出される放射線を測定する放射線強度測定手段と、カートリッジCを保持する保持手段30と、保持手段30を放射線強度測定手段まで移動させる移動手段とからなり、移動手段が、保持手段30がスリット15hの軸方向と直交する方向に沿って移動するように、保持手段30の移動を案内するガイド部と、カートリッジCに充填された状態の全ての線源が収容部の収容空間内におけるスリット15hが設けられている位置を通過するように、保持手段30を移動させる移動部とを備えていることを特徴とする。
