This paper aims to assess thermal performances of the solar field of the Integrated Solar Combined Cycle (ISCC) power plant at Ain Beni Mathar (ABM) in Morocco for the year of 2015. Thus, mathematical modeling of the Schott PTR-70 2008 solar receiver consists of energy balance equations which were solved using COMSOL Multiphysics software. Next, the model was validated with empirical data from the literature, so the comparison is satisfactory. Results analyze daily and annual thermal performances of the plant, and also comparison between simulated and actual plant operating results. Indeed, for selected typical days, it was concluded that the model's predictions seem to be adequate except at the beginning and end of each day. On the other hand, the estimates of cumulative thermal productions for selected ten days of each season were also carried out. Accordingly, the actual operating thermal energy is very close to simulated one for all chosen days since the relative error does not exceed 3.27% in the worse case. Unlike summer season (25.86 GWh in July), the monthly average thermal production is low in winter (about 6.0 GWh), as expected. In conclusion, the annual operating thermal production is about 172.5 GWh/year versus 176.3 GWh/year estimated value. (C) 2020 Elsevier Ltd. All rights reserved.