Each EPIC Camera contains 58 high-precision X-ray mirrors. They can observe in the energy range from 0.15 to 15 KeV, corresponding to wavelengths ten million times smaller than a millimeter.

One of the EPIC cameras, the EPIC-pn CCD, was developed under the leadership of the MPI for Extraterrestrial Physics in Garching. It uses a novel technique, specific for the highest energy signals. Its detector has a surface of 36 cmsq: it is the largest X-ray CCD detector ever built.