100 keV ion implanter for metal surface modification has been constructed. It has two functions

i.e. direct implantation of nitrogen ions with energy of tens to 100 keV into work pieces

or ion beam mixing and recoil implantation adopted for implanting non-nitrogen elements. The overall structure and major parts of the imlanter are described. After tuning the main work parameters

the machine has met the design target. The machine runs stably and reliably and several experiments on metal surface modification are being performed.