In this paper, the production of sintered bodies of electrolytic copper powder using metal powder injection molding (MIM) was discussed. Electrolytic powder suitable for MIM was selected from among three kinds of electrolytic copper powders, A, B and C, with mean particle sizes of 11.27 μm, 18.89 μm and 26.83 μm, respectively. The powder B was most suitable for MIM. To produce sintered bodies of high density, we chose copper powders with low oxygen and carbon contents, and determined the optimum hydrogen treatment temperature. When hydrogen treatment was performed at 973 K for 2 h with a binder content of 42.5 vol%, the sintered bodies had a relative density of 95.6%, oxygen content of 0.001 mass%, and carbon content of 0.001 mass%.