A calculation procedure to determine the energy distribution of interface states from the deep level transient spectroscopy spectrum measured in metal-insulator-semiconductor structures by means of the DLS-82E lock-in spectrometer is described. Interface states in metal-boron nitride-WP and metal-oxide-Si capacitors have been examined by the DLS-82E spectrometer to demonstrate the practical application of the proposed procedure. (C) 1995 American Institute of Physics.