This article presents the principles of scanning thermal microscopy (SThM) instruments and their potential uses for the local thermal analysis of passive and active electronic components and devices. Three examples are given that demonstrate the SThM’s ability to perform thermal analysis on a microscopic scale. The results suggest that SThM could be used as a powerful tool for analyzing printed circuit boards and electronic devices with high spatial resolution, during the development cycle, failure analysis during and after manufacture, and during operation.