This paper deals with the basic theory and the usability of the scanning Kelvin probe (SKP) being a non-destructive, non-contact method for testing the condition of the surface of conductor, semiconductor and dielectric samples. This technique is based on the electron work function (EWF) characteristic of various test substances and depends, inter alia, on the sample surface condition. During measurement, the so-called surface potential distribution map containing information about EWF value is registered. Key applications of SKP and its various modifications to characterization of corrosion interfaces, have been presented based on the newest literature data covering the past two years of the active research in the field of corrosion in a nanoscale.