The integration of atomic force microscopy (AFM) with IR radiation provides a reliable route to bypass the diffraction limit to achieve spatial resolution spectroscopic imaging at a 10-nm scale. As of 2021, two main categories of AFM-based IR microscopy exist based on their detection principles: mechanical detection on the tip-enhanced photothermal response of the sample; optical detection through light scattering from the near field of the AFM tip. This chapter on AFM-based IR microscopy will separately describe the working principles of these two routes, followed by some of their applications in the characterization of energetic materials.