The way of radiation modification of the base and filled compositions of polyethylene of a middle pressure (PEMP) promoting increase on heat resistance, shrinkage drop and warp of radio engineering details and products has been developed. Optimum conditions of stabilization irradiated PEHP  by high-temperature annealing are chosen. The influence high levels of capacities of the high-frequency OHF- radiations on structure and operational properties of various marks PEMP  is studied. Ability of base and modified marks PEMP, in conditions of influence of high capacity of electromagnetic energy, to keep high operational characteristics being perspective constructional dielectric for REA and CRT setting