The XRM-II nanoCT is a nano CT system based on a field-emission scanning electron microscope (SEM). A needle-shaped reflection target, which is installed inside the specimen chamber, in combination with the focusing electron optics of the SEM generate a x-ray spot of about 100 nm. A single-photon-counting direct-converting detector with a CdTe sensorlayer is used for x-ray detection. The system supports a variable magnification range from 100x to 2000x achieved by geometric magnification, which equals a voxel size between 600nm and 30nm.