Mathematical model for temperature fields calculation in targets of magnetron sputtering systems is described. The paper shows the main ways in which the power supplied to the discharge is removed. The results of numerical simulation of the spatial temperature distribution of a magnetic target are presented. The paper also shows the results of numerical simulation, which allow to link the input power and the shape of the target with the distribution of its temperature. For the obtained temperature distributions magnetic induction distributions are calculated taking into account the loss of magnetic properties of a material when its temperature exceeds the Curie point.