An X-ray tube includes: a Wehnelt electrode having a dent inside; a filament arranged in the dent of the Wehnelt electrode and configured to emit an electron beam when electricity is passed therethrough; an anode configured to emit an X-ray in response to the incident electron beam; an electrode part configured by at least one pair of electrode members, the electrode members facing each other across a path of the electron beam, a voltage being applied to each of the electrode members; a voltage controller configured to control the voltage applied to the electrode part; and a shield member arranged in contact with the Wehnelt electrode and configured to cover part of the dent by a projecting part.