For eliminating a high-tension cable in order to improve the handling, the open type X-ray generating apparatus (1) in accordance with the present invention employs a mold power unit in which a high-voltage generating part, a grid connecting line, and a filament connecting line which attain a high voltage are molded with a resin, whereas the mold power unit is secured to the proximal end side of a tubular portion (2), whereby an apparatus of a type integrated with a power supply is realized. Since the high-voltage generating part, grid connecting line, and filament connecting line are confined within the resin mold as such, the degree of freedom in structure of the high-voltage generating part and the degree of freedom in bending the lines improve remarkably.