An X-ray tube controller measures operation information (filament power supply time in an X-ray tube and a grid voltage value applied to grid electrodes to maintain the tube current value under a predetermined tube voltage). The information is transmitted to an X-ray tube operation information acquiring unit via a communication line. In a storage section of the information acquiring unit, a database written with degree of attrition corresponding to the integrated power supply time of a filament (reduction ratio of thermalelectron emission amount (tube current value at a predetermined G1 voltage) to the initial value (thermalelectron emission amount when the filament is first used) is stored. An attrition degree determination section determines the degree of attrition of the filament from the count of filament power supply time with reference to the database. Also, the attrition degree determination section determines the end of life from the G1 voltage value.