The transistor is currently the backbone of semiconductor electronics for its wide applications in the field of amplification or switching of electronic signals. One of the best-known and widely used transistors is the field effect transistor, known as the insulated gate silicon oxide transistor (MOSFET). In recent years, the miniaturization of MOSFETs has attracted a lot of attention. With its reduced size (nanoscale), the heat generated mainly affects the efficiency of the device. In this thesis, the modeling and simulation of heat transfer in the MOSFET using the lattice Boltzmann method is carried out. This method allowed us to study the effect of different physical parameters on heat transfer in transistors such as Robin boundary condition, channel length, reflectivity parameter and type of material used without the need for adding extra mathematical terms. The obtained results showed that all these parameters have an effect on the diffusion of heat and therefore on the performance of the MOSFET. In addition, the results confirmed the ability of the LBM method to simulate the diffusion of heat inside the electronic devices studied.