This study aims at developing a high temperature extruder for an FDM (Fused Deposition Modeling) type 3D printer that uses engineering thermoplastic filaments. An extruder is a key part of an FDM type printer, in which a filament moves to a heating block and is extruded through a nozzle with a specific diameter. For an appropriate extrusion, the filament should be heated above its softening temperature. Specifically, the filament should not be melted nor softened before it reaches the heating block for appropriate delivery. Hence, the extruder temperature should be carefully controlled to ensure its heating capability as well as its proper delivery. To meet these requirements, thermal-structural finite element (FE) analyses were performed for the prediction of the distributions of temperature and thermal stress. Various extruder designs were then considered to maximize the temperature difference between the nozzle and delivery parts, as well as to ensure structural safety.