PROBLEM TO BE SOLVED: To provide a radiation amount management device in which operability in setting a TargetExposureIndex (herein after referred to as an EIvalue), which is a target dose index for an X-ray machine to an appropriate value, is improved.SOLUTION: An ExposureIndex (hereinafter referred to as an EIvalue) is set to an X-ray machine 40. A CPU 14 acquires a plurality of EI values respectively indicating a dose of a radioactive ray that has transmitted through a patient at a time of imaging by the X-ray machine, and calculates a plurality of DeviationIndexes (hereinafter referred to as DI values) respectively indicating a deviation of the acquired EI values relative to the EIvalue. The CPU 14 also displays an EI/DI graph indicating a relationship between the plurality of obtained EI values and the plurality of calculated DI values on a screen of a display device 20, and accepts, on the display of the EI/DI graph, slider moving operation for updating the EIvalue.SELECTED DRAWING: Figure 1