This article investigates the characteristics of optical materials that can be used in the terahertz (THz) spectral range, which falls between the optical and radio ranges. The importance of research fields related to terahertz device optics lies in the enhancement of laser creation activities in the terahertz range and the significant issues discovered in general optical material applications. This study aims to analyze the characteristics of the THz materials used, especially their optical properties. The article provides the characteristics of these materials and discusses and compares the physical, chemical, and optical properties of conventional and new materials, including crystalline materials (silicon, sapphire, quartz, diamond, germanium, and silicon carbide) as well as some polymers (polymethylpentene, polyethylene, and polytetrafluoroethylene).