The progress in near-field infrared (IR) microspectroscopy was discussed using a photothermal probe and its application to the spectroscopic characterization of real-world samples was shown. Among the microoptical techniques, fourier transform infrared (FTIR) microspectroscopy has a prime position within many industrial laboratories. In FT-IR transmission microscopy, for a continuous sample such as an organic polymer film, the sample thickness typically must be 10μm or less. The spatial resolution will be limited simply by the size of the probe and the temperature distribution within the sample, rather than the infrared wavelength using photothermal microspectroscopy (PTMS).