We have investigated the magnetic electronic structures of PtMnSb, Ni2MnSb, Ni2MnSb,MnSb, MnAlGe, and Mn2Sb by soft-x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) measurements in the Mn 2p core absorption region. Different degrees of the electron itinerancy of the Mn 3d states are discussed. The large orbital angular momentum of the Mn 3d electrons is revealed for MnSb by the MCD spectrum. In addition, the XAS and MCD spectra are measured in the Sb 3d, Ni 2p, and Pt 4f core excitation regions. An induced magnetic moment of Sb valence orbitals with the spin antiparallel to that of Mn is clearly indicated for NiMnSb and Mn2Sb.