An X-ray generation device includes a cathode including an electron source generating an electron beam, an anode including a target to transmit an X-ray generated by collision of the electron beam, and a convergence electrode converging the electron beam toward the target. The target has a first region having a locally small thickness and a second region having a larger thickness than the first region. The X-ray generation device further includes a deflection unit to switch an incident position of the electron beam between the first region and the second region. The deflection unit has an adjustment mode to adjust an X-ray focal spot diameter and an X-ray generation mode to generate an X-ray, the electron beam is caused to enter the first region in the adjustment mode, and the electron beam is caused to enter the second region in the X-ray generation mode.