We investigate the effects of the ambient temperature (T), both temperature (T a )and time (t a )of annealing on the electrical conductivity (σ), and the Seebeck coefficient (S) of Sb2Te3. We concluded that both holes and electrons can participate to the conduction process. The material behaves as a semimetal. Although the Seebeck coefficient possesses a plus sign, the coefficient of S vs. plots was negative as a degenerate semiconductor. The decrease in value of S with increasing t a was attributed to a corresponding decrease in the amount of positional disorder which acts as an electron trap center.