X射线管是能够发生X射线的一个设备或设备的部件。

X射线管都包含阴极和阳极组件，其皆位于真空的材料密封罩内亦即为真空管。

• 阴极组件

其是由钨丝绕成线圈的形式装在一个浅的聚焦杯（focusing cup）中，当钨丝通过足够的电流时，使其产生白热现象时电子会从钨的表面逸出形成电子云。

• 阳极组件

主要为钨靶，通常是由钨或钨铼合金所制成，其作用在于使阴极来的高速电子停止运动。

An X-ray tube is a vacuum tube that converts electrical input power into X-rays. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered on November 8, 1895, by the German physicist Wilhelm Conrad Röntgen. The availability of this controllable source of X-rays created the field of radiography, the imaging of partly opaque objects with penetrating radiation. In contrast to other sources of ionizing radiation, X-rays are only produced as long as the X-ray tube is energized. X-ray tubes are also used in CAT scanners, airport luggage scanners, X-ray crystallography, material and structure analysis, and for industrial inspection.