The results of a study of the destruction of biological tissues by high-frequency electromagnetic radiation at an allowed frequency of 27.12 MHz are presented in comparison with destruction also at an allowed frequency of 13.56 MHz with the same power of the acting radiation of 30 W. Today, all known devices for high-frequency electromagnetic destruction at a frequency of 27.12 MHz are used for superficial shallow operations (removal of papillomas, moles, etc.). The development of a high-frequency electromagnetic system for the destruction of deep, dense tissues (bone, cartilage), as well as malignant neoplasms at the indicated frequency, is the most urgent task of our time. To conduct research at the indicated frequency, an experimental setup was developed and implemented on a modern element base, a distinctive feature of which is ensuring stable and reliable operation of the used transistor power amplifiers while maintaining their performance in a wide range of load changes (from idle to short circuit). This feature is implemented through the use of a two-channel bridge amplifying path. To test the operability of the installation, a multimeter with a thermal imager function and an immitance meter were used. The form of the output signal of the installation is a sinusoid, the second harmonic is weakened in relation to the main one by 60 dB. The studies were carried out in vitro on biopsies of muscle, bone tissues and liver of cattle, as well as on pig skin. It is shown that cuts of a biological tissue made at a frequency of 27.12 MHz have deep coagulation, and at a frequency of 13.56 MHz, carbonization of muscle tissue is already observed at the site of coagulation; the destruction of a bone tissue and liver at a frequency of 27.12 MHz is more pronounced, at a frequency of 13.56?MHz, elements of carbonization appear in the area of destruction. The exposure to high-frequency radiation at a frequency of 27.12 MHz occurs with a smaler effect on surrounding tissues than at a frequency of 13.56 MHz, Punctures of muscle tissue and liver performed at various frequencies practically do not differ; the temperature in the electric discharge region, which occurs at a frequency of 27.12 MHz at a radiation power of 30 W, is above 150 ° C (at a frequency of 13.56 MHz the temperature is 126 ° C).However, the temperature in the discharge region at a frequency of 27.12 MHz can be reduced to the same temperature as at a frequency of 13.56 MHz by reducing the power of electromagnetic radiation by a factor of 1.5.