It was found that when an electric current with a density of 45.6·106 A/m2 is passed through a carbon fibre for 15 sec, its temperature increases to 950@deg;C. This causes the total elimination of sorbed moisture, oiling agent, and surface contaminants, and increases the filament strength to 3640 MPa, which is 18% higher than for fibres undergoing “wet” treatment with nitric acid. Thermoelectric treatment of carbon fibre in nitrogen medium with subsequent impregnation with a binder and molding of a prepreg is inserted in the existing technological process and allows increasing the strength of carbon–filled plastics by 10-34% without significant losses. Stable molding of the prepreg is ensured for a fibre draw rate through the unit of 1.1 m/sec and tension of 80 N by treatment with a 10.5 A electric current with a potential difference of 60 V, nitrogen flow rate of 22.5 liter/h, and calibrated spinneret hole diameter of 0.67 mm.