In the present work, the main characteristics of a Combined Cycle Full Scope Simulator for Operators´ Training (CCS) developed by the Electrical Research Institute (IIE) of Mexico are described. The simulator is installed in the National Centre for Operator’s Training and Qualification (CENAC), the capacitating entity of the Electricity Federal Commission (CFE, the Mexican electrical utility company). In general, the models were developed using the basic conservation principles of mass, energy and momentum. However, due to some particular circumstances a simplified approach to simulate some systems was adopted. The causes of this resolution and some results of the simulator are also presented in this paper.