The known process as Metal Injection Molding is derived from the conventional powder metallurgy (M/P) being an alternative for production of parts with complex geometry, great dimensional precision and freedom of chemical composition. The present work has the objective to evaluate the processing of the Fe3Si alloy sintering in the vacuum furnace using as raw materials iron powder carbonyl and prealloyed powder Fe45Si with D90<10-m. Properties of microhardness, density, coercivity, magnetic permeability, and chemical composition was evaluated. The obtained results were compared with what is presented in the literature for parts processed by conventional ways and with parts processed by M/P. A density of 7,620 kg/m3, a coercive field (Hc) of 101.14 A/m, a relative maximum permeability of 5,484 and a residual induction of 1.1 T was achieved by MIM. Comparing with conventional processes (where 100% of densification is reached), the MIM process results were worse, however they were better than P/M.