We discuss a soft X-ray emission (SXE) valence band (VB) spectroscopy method for the study of the electronic structure and chemical phase composition of solids in a near-surface region with depth resolution. The depth information is obtained by variation of the energy of the incident electron beam used to excite the SXE spectra As the information depth can be varied from about 1 nm to 1 mm in silicon, this method is suitable for the investigation of materials of modern micro- and nano-electronics. VB -> core level (Si 2p or A1 2p) transitions in Si- based materials are used to demonstrate the technique. It was found that the contribution of the signal from the nearsurface region (<1.5 nm) can be substantial (up to 50%) when the primary electron energy does not exceed the Si L _2,3 threshold by more than 150 eV. The technique is applied to Al impurities in a Si matrix, produced by ion implantation. The electronic structure at the Al sites and the depth distribution of the A1 impurity change markedly after post implantation annealing. The observed electronic structure after annealing is in agreement with electronic structure calculations for substitutional Al impurities in a crystalline Si lattice.