A new low-cost absolute cryogenic radiometer of the electrical substitution (ES) type optimized for performing black-body models calibration is described. Nitrogen is used as a cryogenic liquid for cooling of a radiometer receiving cavity up to temperature 80 K. This absolute ESR has been developed for measuring the irradiance in the range of 10-3 divided by 10-6 W/cm2 with the uncertainty of 0.1% for the upper level of irradiance range. The receiving cavity having 16 mm aperture, is fabricated from copper foil with thickness of 30 micrometers . A substitution winding of the receiving cavity is made of manganin wires. Measured heat conduction of the receiving cavity is 1.1 X 10-3 W/K. A single time constant of the receiving cavity is 80 sec. Brief description of the design, operating principles, and measurements results of the new cryogenic radiometer at nitrogen temperature are given.