Abstract In this work, a process for the assembly of a standard triple Gas Electron Multiplier detector and the study of the main variables was made at the Universidad Antonio Nariño, Colombia, detectors laboratory. The triple gas electron multiplier was tested with Ar/CO 2 mixtures in proportions of 70/30%, 80/20% and 90/10% using a 55 Fe X-ray source (5.9 keV). The energy spectrum, energy resolution, effective gain and ionization rate were analyzed according to the applied voltage and the Ar/CO 2 gas mixture. The Universidad Antonio Nariño, Colombia, triple gas electron multiplier detector obtained an energy resolution of up to 19% and an effective gain close to 10 4 ; where the detection efficiency is approximately 95%. These results were compared with other studies to check the triple gas electron multiplier performance.