Abstract: An electronic feeler gauge and a method of using the same which provides an objective means of determining the width of a gap between two surfaces. The gauge comprises a measuring element which is insertable into the gap and an indicator coupled to the measuring element for automatically indicating when the gap has been set to a predetermined distance. The measuring element comprises two plates which act as an electrical switch in an electrical circuit. When the gap gauge is inserted into a gap of predetermined width, the plates press against each other and current from a power source lights up a light emitting diode. Conversely, when the plates are inserted into a gap that is too wide, the plates do not press against each. The circuit, therefore, is not complete, and the light emitting diode does not light up. Thus, this invention provides an objective, reliable means for confirming the width of a gap. The invention can be used for gaps of different widths by varying the thicknesses of the plates.