In this paper, a new model of electric power supply-demand analysis based on a clustered unit commitment model is proposed. This method enables to derive daily generation plans in multi-area by minimising daily generation cost. In the clustered unit commitment model, the generation units are clustered for the purpose of saving calculation time of the optimization. The proposed model is formulated by Mixed Integer Linear Programming (MILP). The numerical experiment of annual supply-demand analysis was done to evaluate the availability of the proposed model. As a result, the availability of proposed model was clarified in the view of calculation time and operational results, which are derived by the numerical experiment.