The spreading resistance probe technique of measuring resistivity in epitaxial layers requires precise control of the parameters that affect the area of contact and damage under the probe. The effects of these parameters on the measurements are described and the design of a semiautomatic probe is presented. The probe can be lowered with the same velocity during each measurement and theIRdrop across the contacts is kept independent of resistivity. The mechanical design and the electronics of the probe are discussed in detail. The reproducibility of the measurements is found to be independent of resistivity in the constant voltage mode and is compared with the customary constant current mode. The (3&sgr;) multioperator reproducibility of the measurements is better than ±0.39% for n‐type silicon and ±0.65% for p‐type silicon.