Functional metal-ceramic composite based on pure iron with magnesia secondary phase was prepared by microwave sintering. Fe powder and 13.85 wt. % of MgO nano-powder were homogenized by resonant acoustic mixing. Mixture was cold pressed at 600 MPa. Single mode microwave sintering device with cylindrical cavity size of diameter 28 mm and height 80 mm was used. The influence of sintering conditions on microstructure and properties of the composite was investigated. Structure, mechanical and electromagnetic properties depend on time-temperature profile of the sintering process. Kinetics of Fe-MgO microwave sintering in air atmosphere was studied. Reproducibility of microwave sintering process was evaluated also. Structural analysis was focused on development of microstructure and transformation of MgO nano-particles induced by microwave sintering.