The possibility to use the scanning thermal microscope for a quantitative determination of the local heat conductivity, at material surfaces is evaluated and critically discussed. Two different methods of operation have been applied: the determination of the probe to sample heat flux in the local thermal analysis (LTA) mode and the analysis of heat flow data derived from thermal maps in scanning experiments (SThM). Both methods lead to a comparable accuracy in the determination of;. The SThM shows the highest sensitivity for small;, and is useful in a X range between 0.05 and 20 W/m K. Finally a new multiwire calibration standard is introduced. (C) 2004 Elsevier B.V. All rights reserved.