PURPOSE: To facilitate replacement of X-ray tube and restrict the ill influence of insulating oil degrading by coupling a tube pack with the body part of X-ray generating device concerned by a high voltage socket and plug, and thereby embodying the X-ray generating device in a consolidated structure.

CONSTITUTION: A tube pack 10 has an independent vessel 10a, in which such components are encapsulated as X-ray tube 1, stator coil 2 for rotating the positive electrode of the X-ray tube 1, insulating oil 8, rubber bellows 3, terminal 13 to be connected to a stator driving power supply, and lead plate 9 for protecting against unnecessary X-rays. The envelope 19a of the body part 19 accommodates transformers 5, 6 to supply a high voltage to the X-ray tube 1 and a rectifier 7, and therein insulating oil is encapsulated. The tube pack 10 and body part 19 are coupled electrically by a high voltage plug 12 and high voltage socket 11 to consolidate the structure of the X-ray generating device. This permits easy replacement of the X-ray tube 1 and precludes the high voltage generating device from being influenced by degradation of the insulating oil 8 resulting from the heat emitted by the tube 1.