Abstract: The work carried out numerical studies of the dynamics of plasma parameters in a microwave discharge in a tube in argon at low pressures. Numerical calculations were carried out for various values of the discharge power input and taking into account the gas flow. The results demonstrated that at a pressure of 10 Torr and power input into the discharge of 100 and 1000 W, the gas temperature in the discharge reaches values of 304 and 345 K, respectively.