The present invention relates to an X-ray tube with a structure, by which the charging of an insulating member, disposed inside a container, is effectively prevented to enable stable operation to be secured. This X-ray tube has an electron source that emits electrons, a target that generates X-rays in response to the incidence of the electrons, first and second electrons, each having a side face portion that extends along the direction of incidence of the electrons and forming a predetermined electric field between the electron source and the target, and an insulating support member, for supporting the first and second electrodes, being disposed along the side face portions of the first and second electrodes. The second electrode, of the first and second electrodes, is positioned closest to the target and has an anti-charging edge portion that is positioned at an X-ray generating surface end of the side face portion and that extends toward the exterior of the container so as to cover over the support members from the target.