Relevance: The effectiveness of removing concretions using sialoendoscopy depends on the size and location of the concretion in the salivary gland. According to the results of the researchers, the predominant intracorporeal lithotriptor is the holmium YAG laser in the crushing of urolites and sialolites. However, to date, in comparative studies of lasers of different types in urology, the thule laser FiberLase U2 demonstrates high efficiency. The research of urologist surgeons served as the basis for conducting an experiment on the possibility of crushing sialolites. The aim is to evaluate the safety and time of crushing of sialolites with a thulium laser FiberLase U2 in vitro. Materials and methods: 12 round-shaped sialolites with a diameter of 5-6mm were selected for the study. We have developed a model simulating the duct of the gland. The fiber of the FiberLase U2 laser was fed through the proximal end of the model and a series of lithotripsies were carried out sequentially in three modes of the device at maximum and minimum values of energy and pulse frequency, fixing the temperature rise during irrigation and the resulting effects during crushing. Results: crushing of sialolites to fragments with a size of 1 mm is possible in all three laser modes. Operation at the maximum values of the pulse energy and frequency proceeded faster, while the maximum temperature rise varied from 45 C to 48 C, depending on the mode. Crushing was accompanied by pronounced cavitation, frequent sparks when the laser pulse was applied. Fragmentation at the minimum parameters of the pulse energy and frequency proceeded much slower, however, the maximum temperature rise remained in the range from 33 C to 40 C, the listed effects were observed to a lesser extent in all three modes. Conclusion: the use of a thule laser for crushing concretions in all three modes at the maximum values of the pulse energy and frequency is inefficient and unsafe, work in the minimum values of the Dusting and Popcorning modes has shown the best results, however, further study of crushing with this laser is necessary.