In this work, copper nanopowder was prepared by utilizing the wire explosion technique in different ambient gas. Ambient gases being used were argon, nitrogen and argonnitrogen mixture. The ambient gas pressure was 500 mbar. Copper wires with diameter of 125 μ m and length of 6.1 cm were used. The powders being prepared were evaluated by transmission electron microscope (TEM) and X-ray diffractometry (XRD). Current and voltage signals were obtained to investigate the wire explosion process and energy deposition into the wire during the discharge.