The article discusses the task of improving the thermal stability of a device used in a rubidium frequency standard. It considers the entire standard and its gas cell, justifying the need for thermal stabilization. To combat temperature  instability, which can negatively affect optical elements in the device, a new thermal stabilization system for the gas cell of a quantum frequency standard was developed. Laboratory tests of the quantum discriminator in a thermal  chamber showed excellent performance, with a resistance change of the thermistor in the bridge being 2 times lower than in the previous circuit. The use of an instrumentational amplifier, which reduces the error signal in the bridge,  and a PID (proportional-integral-derivative) controller, which corrects transients and provides stable and accurate regulation, while protecting the circuit from overshoots, have been proven effective. With the help of thermal  stabilization, the short- and long-term stability of frequency and time standards can be further enhanced, which will positively affect the synchronization of time scales in satellite navigation systems.