Abstract: The present invention discloses a non-thermal plasma treatment of metal powders in order to improve their processability by additive manufacturing (AM). The invention consists in bonding primary particles constituted of metals or metal alloys to a plurality of secondary particles constituted of metals, metal alloys, ceramics or polymers by the mean of a non-thermal plasma treatment. The primary particles have a larger mean diameter than the secondary. Both particles are injected through a non-thermal plasma glow discharge and/or in its afterglow region (region downstream the plasma discharge) where their surfaces are cleaned by removing contaminants and/or oxide layer and activated to react between each other. The functionalized metal powders are then collected and afterwards processed by AM leading to high quality parts. The functionalized metal powders produced by this plasma treatment improve the processability of metal by AM.