In metal/insulator/semiconductor structures, capacitance–voltage characteristics and capacitance or voltage transients can be measured in different conditions, which are described and implemented. Each method contains information about charges which are accommodated, captured, or emitted by energy levels or bands at interface and inside the oxide. Pulsed capacitance measurements and differential isothermal procedures are analyzed and performed. Calibration of the energy scale from the interface potential as a function of the applied voltage and extraction of the interface state spectra and characteristic response times independently are possible with the help of signal processing by Fourier transform of transients at one or few selected temperatures. Different trap filling conditions may help to discriminate between interface and oxide states. These methods are applied to Al/SrTiO3/Si capacitors as an example.