In this paper, economic and environmental objectives are investigated in the unit commitment (UC) problem. Considering forecasting error of wind power, multi-objective stochastic model is formulated as the form of expected values, occurrence probabilities and confidence levels. While deterministic approaches use a point forecast of wind power output, forecasting error uncertainty in the stochastic UC alternative is captured by a confidence interval. The numerical simulation illustrates that the suitable confidence level in operating reserve constraints is related to error distribution of wind power forecast. Moreover, the potential risks of spinning reserve shortage show clearly lower on account of suitable confidence level.