PURPOSE: To make setting of the anode voltage and cathode voltage of a metal X-ray tube to the same value using a simple configuration by interposing an inductance between a resonance capacitor and either one of the two transformers.

CONSTITUTION: The output of a resonant inverter 7 supplied with power is fed to the primary windings of a pair of transformers 4A, 4B through a resonance capacitor 6. The outputs from their secondary windings are fed to the cathode and anode of a metal X-ray tube 1 with metal part 1A grounded through respective rectifiers 3A, 3B. Therein the capacitor 6 constitutes a resonance circuit with the inductance of each transformer 4A, 4B, and their resonance frequencies are made different, for example by interposing a corrective inductance 5 between the capacitor 6 and transformer 4A so that the anode voltage and cathode voltage of the X-ray tube 1 are set to the same value.