A miniature X-ray source includes a support structure provided with a through hole, an anode arranged at one end of the hole and a cathode at the other end of the hole, thereby defining a cavity, wherein the anode and cathode are adapted to be energized to generate X-ray radiation. The support structure has a cross-sectional shape that is determined such that a desired radiation distribution of the radiation generated by the X-ray source is achieved. Also a method of manufacturing miniature X-ray sources is disclosed.