The article presents a numerical study of the gas hydrate dissociation model in a reservoir under the action of microwave electromagnetic radiation at 400 MHz, 1 000 MHz, and 2 450 MHz. The decomposition of gas hydrate under this influence is faster at lower values of the reservoir’s initial hydrate saturation. The effects of 1 000 MHz and 2 450 MHz frequencies are much stronger than those of 400 MHz. The study shows that during heating times higher than 400 hours, 1 000 MHz frequency radiation electromagnetic heating is more efficient than that of 2 450 MHz frequency. Using the proposed mathematical model, it is possible to determine the optimal frequencies of the radiation source at a given time of heating the reservoir of a particular field. Moreover, the resulting calculation of energy efficiency (EROI ≥ 10) of this method for gas hydrate-extracted gas proves its competitiveness when compared to traditional methods of thermal impact on the reservoir.