In recent years, more and more dry resins have been used for diversifying raw materials. For this reason, vent type injection molding machines which do not require preliminary drying have attracted attention. Only the plasticizing mechanism is different from the conventional inline screw type injection molding machine, and the process of molding process is exactly the same. The vent hole is provided at an intermediate position of the cylinder. Others are the same as conventional inline screw type injection molding. Vent up trouble, resin change and contamination are sufficiently solved by reliable supply of raw materials adopting special screw design and hungry molding method. The temperature setting is also different between the vent injection molding machine and the usual inline injection molding machine. These differences are away from workers' common sense. In this study, the temperature setting of the vent injection molding machine is reported.