The internal junction temperature of an IGBT is the key element of confining life period of components. Meanwhile, during the IGBT works as a switch in a half bridge circuit, it usually arrives at a high temperature level about 150 °C to 175 °C, due to the accumulation of heat in the junction of IGBT. Thus, a large quantity of energy is lost in the form of heat. This paper focuses on the reduction of the internal junction temperature of the IGBT using a thermoelectric module (TEM), also known as thermoelectric generator (TEG), sitting between the IGBT component and heatsink. As an application of thermoelectric energy harvesting, this technique combines a cooling system equiped TEM for the IGBT and electrical energy harvesting. Moreover, for the optimal load, the maximum electrical harvest power arrives at 0.5 W. Finally, based on the experimental results on two comparable models, we could prove that the cooling system with the TEM reduces internal junction temperature of the IGBT by several degrees. Consequently, with this cooling system, the IGBT could work at a higher current and several electrical energy is harvested.