This manual explains the operating method, data analysis method, and precautions of Fourier Transform Infrared Spectroscopy (FT-IR). It is published to be used when using equipment by providing tips on the utilization of the equipment. The FT-IR is equipment through which information on the molecular motion of a particular correctly-functioning molecule can be obtained by measuring the level of absorption (or permission) while the absorption of energy equivalent to the vibration and rotational flow between molecules with polarity if IR rays are applied to the sample. The FT-IR-based analysis includes the molecular structure of organic and inorganic compounds, structure of unknown compounds, unknown samples through a functional group test, and response speed. In addition, the measurable samples are organic matters, agricultural chemicals, drugs, synthetic resin, industrial products, petroleum compounds, natural substances, and polymer compounds. In addition, most organic and inorganic materials in solid, liquid, and gas states can be analyzed.