The quasi-static capacitance of amorphous As₁₀Se₉₀ thin films was studied in cycles of heating and cooling near the glass transition temperature T_g=343 K. Features in the capacitance behavior such as: non-exponential relaxation, non-Arrhenius character of time relaxations, hysteresis of temperature dependence, physical ageing - are revealed near this temperature. It was accepted, that the capacitance measurements allow finding the glass transition temperature T_g in amorphous As₁₀Se₉₀ thin films which is accompanied by freezing of some electric dipoles; these dipoles are forming from neighboring pairs of charged defects such as D⁺ and D^-.