New vitreous composite materials (CMs) with two magnetic subsystems are synthesized by impregnation magnetite-containing matrices from iron-containing nanoporous glasses in aqueous MnCl2 and H2C2O4 solutions and the subsequent formation of manganese oxides MnxOy (x = 1, 2, 3; y = 1, 2, 3, 4) inside the pore space of the matrices as a result of thermolysis of the reaction product of the dopants (MnC2O4). The chemical (elemental) and phase compositions, the valence-coordination state of iron and manganese, and the characteristics of the magnetic state of the synthesized CMs are studied and compared with the characteristics of nanoporous matrices.