A new technique for anomalous skin‐effect studies is described. At low temperatures (∼4°K) it measures both surface reactance and surface resistance over a wide band of frequencies extending to below 100 cps. For the transition region from classical to anomalous behavior, experimental results on high‐purity copper show excellent agreement with theory, assuming diffuse scattering of electrons at the metallic surface. A new numerical table of theoretical values is included.