There are many products made of long and thin shaped materials characterized by their superior flexibility and strength. The original technology required to transform the raw material into linear, planar or even cubic shaped products can be found in textile industry. Especially, the technology concerning manufacturing linear shaped products is used in staple yarn formation, which has a great influence on the efficiency and product quality of the sequential processes. The qualities of the staple yarn are assessed by many factors mainly tested on the basis of the static measurements, i.e., texture, color, surface roughness, etc.. These factors are closely related to the thickness of yarn. In this study, we try to introduce a new measuring method that can indentify the thickness of yarn using a flying spot laser beam. The results show that this system can deliver data in a stable and reproducible way under a constant condition. But the variance of the measured values is dependent on the yarn feed speed, which can be attributed to the dependence of the probabilistic distribution of the measured values on the sampling length interval