The invention relates to a method and an installation for identifying an object. An identification mark (12) is made on the actual object using electrical discharges (28) between a metal tip (21), such as that of a local-probe microscope, and the substrate (22) formed by the object. The discharges (28) are produced through a composite dielectric medium (25) and produce an impression (23) which can be identified by read means, such as a microprobe, and has a particular physical nature and/or a particular chemical composition. Thanks to these characteristics, it is possible to obtain a very secure identification and authentication mark that can be applied directly to the actual object to be identified or authenticated.