The microspectral film thickness detector uses the structure of a microscope to accurately measure the reflection spectrum of tiny or ultra-thin samples that cannot be measured by general spectroscopic instruments. It will not interfere with the reflected light from the back of the sample. Therefore, it is a microscopic spectroscopic detector suitable for detecting and evaluating the coating quality and the reflection spectrum of small samples, and can simultaneously analyze the film characteristics. Through the measurement and analysis software i-Spec, professional thin film technology is integrated into a simple and intuitive system, allowing operators to use the instrument in just a few minutes of teaching. Modular system integration and self-developed software can be customized and planned according to customer needs for production line inspection and film thickness measurement systems.