A noncontacting electro-optical probe is presented that is capable of monitoring the surface height of a sample in ranges of interest for mechanical tooling machines. The surface microtopography is reconstructed after scanning. The working principle is based on monotonic longitudinal chromatic aberration of a lens. Characteristics of a designed lens are reported, along with interferometric testing data on a fabricated prototype. Calibration curves of the complete device are given. After interfacing to a personal computer, automatic probing and scanning are implemented. Results on selected samples are presented.