Patent ID: 7680248

Claim:
An X-ray tube comprising: a vacuum cabinet inside of which is brought into a vacuum state and which includes a window portion formed by an X-ray transmitting film through which an X-ray is transmitted; an electron beam source installed at inside of the vacuum cabinet for emitting an electron beam; a target for generating a primary X-ray by being irradiated with the electron beam and installed at inside of the vacuum cabinet to be able to emit the primary X-ray to an outside sample by way of the window portion, wherein at least one of the target and the window portion is set to a ground potential or a plus potential; and an X-ray detecting element arranged at inside of the vacuum cabinet for detecting a fluorescent X-ray and a scattered X-ray emitted from the sample and incident from the window portion for outputting a signal including energy information of the fluorescent X-ray and the scattered X-ray.