The electron energy distribution function in the afterglow of a low-pressure discharge in an Ar-N-2 mixture was experimentally found. The values of electron temperature were determined. At the initial stage of plasma decay, the electron temperature was shown to be close to the nitrogen vibrational temperature. A study was made of the afterglow observed in the bands of the first negative system of N-2(+), and it is shown that this afterglow may be attributed to collisions of argon ions with nitrogen molecules found on higher vibrational levels. (C) 2000 MAIK "Nauka/Interperiodica".