The knowledge on the material production from archaeological sites contains valuable information on the technological advances and on the commercial routes of a civilization. Archaeologists can face some ambiguities in the assessment of the productive function of furnaces emerging from excavation when archaeological markers are not available due to a poor conservation state. A protocol to discriminate among the production of lime and ceramics is the major aim of this work. Indeed, herein, we address the possibility to assist archaeologists by a vibrational spectroscopy‐based identification of furnace productive function using a proper sampling, particularly to discriminate between kiln for ceramics from calcara. The proposed analytical procedure supported by a geological survey of the area was established, defining also the application limits, by investigating four cases, one from the sanctuary of Hera at the mouth of river Sele (Paestum), two from Velia (Eastern and Southern quarters), and the fourth from Roscigno. Some care during sampling from furnaces and in the interpretation of possible interferences in Raman and FT‐IR spectra are also discussed.