Abstract: An X-ray tube and an X-ray inspection apparatus using the X-ray tube have improved workability of the baking for obtaining an ultra-high vacuum of the X-ray tube having a field emission type electron gun, and have stable performance. The X-ray tube includes a field emission type electron gun chamber, an electron beam aperture, an X-ray target and a vacuum pump in one body with a vacuum sealing structure (vacuum tube section). The vacuum tube section is attachable and detachable to an electromagnetic lens section in the X-ray tube. It is thereby possible to perform the baking by removing only the vacuum tube section. Fitting portions for positioning are provided at the vacuum tube section and the electromagnetic lens section to easily perform an optical axis alignment at a mounting time after the baking.