Energy distribution of low energy (0.2-2.5eV) electrons was measured by means of Langmuir probe at eleven o'clock J. S. T. on the 13th, February, 1982 over Kagoshima Space Center, Japan. Second derivative of the V-i curve which is necessary to get the energy distribution function was obtained by means of the second harmonic method. The second derivatives obtained at lower ionosphere (90-150Km) showed clear peaks at the energies which correspond to the wave length of excited gas emissions. Some of these peaks were identified as due to O and O₂. The results conclusively suggest that electrons of thermal energy range interact with ambient excited neutral (and/or ionized) gases and gain energy from them.