We study the random telegraph signal (RTS) due to defects at the Si/SiO2 interface of a MOSFET in a microwave field. We observe the change of the characteristic times of the RTS by monitoring the drain current in such device operated under microwave irradiation and the change of the emission/capture time ratio. The random telegraph signal is examined as a function of the microwave power from the temperature of 1.6K to room temperature. We observe a common trend in the RTS modification for all the investigated traps at all temperatures. The effect of increasing the irradiated power is to decrease the emission and capture times, while their ratio may depend on the temperature.