This diploma thesis deals with the design of injection molds, especially it is focused on their temperance and cooling. The aim is to design a beneficial technological process for tempering and cooling the injection mold for critically exposed sites. In the theoretical part I focused on a comprehensive outline of the issue of injection molding and the possibility of tempering and cooling circuits. In the practical part the specified injection was modeled and an injection mold was designed for its implementation. The construction was carried out in the Siemens NX program and the simulation analysis was done in Cadmould 3D - F and Aeroflow software. For the POM material the total shrinkage and warpage of 1.674 [mm] and the flatness of the hem of 0.403 [mm] at a total optimum mold temperature of 80 [°C.] were achieved. For PA material were total shrinkage and warpage 1,745 [mm] and flatness of hem 1,649 [mm]. I researched that the maximum mold temperature at POM injection is 94.862 [° C] and the end temperature at the end of the cycle is 87.259 [°C] at a critical point. The main finding is the possibility to affect the overall shrinkage and warpage along with the flatness of the hem by varying the temperature of the cooling circuits. Based on the detected data, the active cooling circuit is more suitable for installation than the passive cooling element. The results of this work enable shortening of the technological cycle time of the injection mold and selecting of a suitable cooling solution for exposed injection sites.