The GEMPix detector combines existing CERN-developed technologies - GEM (Gas Electron Multiplier), a type of gaseous ionisation detector and Medipix, a family of photon-counting pixel detectors. In combination, the features of each technology are enhanced and the resultant technology is a hybrid device able to detect all types of radiation with a high spatial resolution. The purpose of this technology is to measure and visualise the low-energy deposits in gas or tissue-equivalent samples. Due to the wide gain range of the chamber, the new device could also be used to measure particle beam structure (i.e. protons and carbon ions) in hadrontherapy with good spatial resolution. It may be used also for X-ray monitoring in burning plasmas physics.